CT-7567

"“I used to believe that being a good soldier meant doing everything they told you. That’s how they engineered us. But we’re not droids. We’re not programmed. You have to learn to make your own decisions.”""―Rex to Dogma on the arrest of General Krell"

Biography
CT-7567 was a veteran clone trooper captain who led the Grand Army of the Republic's acclaimed 501st Legion during the Clone Wars. Bred and trained on the planet Kamino, CT-7567 entered into Republic service at the Battle of Geonosis in 22 BBY. He gained respect from Jedi officers and clone troopers alike as an honorable commander, becoming known as one of the best and toughest clone troopers in the Grand Army. He was even selected for special command training under Advanced Recon Commando Alpha-17, following which he took the nickname "Rex." As the captain of the 501st, Rex served as second-in-command to Jedi General Anakin Skywalker, whose bravery and unorthodoxy in battle he came to share. He was close friends with Marshal Commander Cody, with their relationship mirroring that of their respective Jedi Generals, Skywalker and Obi-Wan Kenobi. The four of them often received joint assignments to coordinate front-line campaigns against the Confederacy of Independent Systems.

At the Battle of Christophsis, Rex became a mentor to Skywalker's newly assigned Padawan, Ahsoka Tano, with whom he forged a strong bond. He also managed to rebound from the following Battle of Teth, an engagement he would never forget due to the near-complete eradication of his 501st unit, Torrent Company.

Early Life
CT-7567, otherwise known as "Rex", was born in 32 BBY, created from the DNA template of the original host, Bounty Hunter Jango Fett. He was created on Kamino by the Kaminoans. There, he would be trained and bred for war specifically. During his training, he would meet fellow clone, CC-2224, otherwise known as "Cody". There, the two would form a unique friendship and fight well alongside each other. His early life largely involved flash training, in which he excelled at. There, his leadership would catch the attention of Advanced Recon Commando Alpha-17. He, along with Cody and several other clone troopers trained under Alpha-17, excelling greatly. By 22 BBY, Rex was promoted to the rank of Clone Captain and given his own clone trooper legion and clone trooper company.

First Battle of Geonosis
Rex participated in the First Battle of Geonosis, much like several other clone troopers who were sent to Geonosis under the command of Grand Jedi Master Yoda. There, Rex and his unit would fight bravely against the Separatist droid army, resulting in a Republic victory and also the start of the infamous Clone War.

The Clone Wars
With the Republic and the Separatist declaring war on each other, Rex, along with all other clone troopers within the Grand Army of the Republic would be assigned to a Jedi General to fight alongside throughout the war effort to assist in the eradication of the Confederacy of Independent Systems. It was just a few days after the Battle of Geonosis that Rex was assigned to newly appointed Jedi Knight Anakin Skywalker.

Battle of Tibrin
After public knowledge of Separatist leader Count Dooku executed the governor of Tibrin, the Republic then sent a Republic fleet to the planet of Tibrin. Rex, along with the 501st Legion went to the planet surface with Skywalker, along with Kenobi and the 212th Attack Battalion. There, it was then that they all witnessed the battle and more than referred to it as a massacre. It was there that the Republic forces decided to retreat, resulting in a victory for the Confederacy of Independent Systems.

Leader from the Front
Gruff, no-nonsense, and tough as carbonite nails, the elite CT-7567 was an aggressive and battle-scarred veteran of the Clone Wars. Hardened by countless engagements with the Confederacy of Independent Systems, Rex—as he chose to be named—retained a reputation as one of the best and toughest clone troopers in the galaxy, particularly due to his near-flawless military record. Freethinking, fearless, and resilient, he preferred to be more diplomatic than the headstrong Advanced Recon Commandos when it came to operating with his superiors, though he would not hesitate to give higher-ranking Jedi officers his blunt opinion. He regarded his assignments with the utmost priority, and true to his genetic engineering, he often put them before his own safety, recognizing the importance of doing his part to ensure an objective's completion. A cunning warrior who was versed in military strategy, Rex led from the front and, in some cases, would have fought ahead of his Jedi General, Anakin Skywalker. Far from being recklessness, his courage and willingness to jump into the fray helped the Republic win numerous victories. His outspokenness and aggression notwithstanding, he held that it was a soldier's duty to follow orders, faithfully executing them even when he disagreed, with little concern for his own well-being. Although he was willing to lay down his life for victory if need be, he came to acknowledge that in some cases, soldiers had to make their own decisions.

Brave and selfless, Rex was resolute in his dedication to his comrades. He recognized the need for galactic order and believed that the war was crucial to preserve the civilization that the Republic safeguarded. In spite of sometimes disagreeing with the management of the Republic's war effort by the Jedi High Council and the Galactic Senate, he remained committed in his service to the Republic. While on the war's front lines, he often become concerned for the safety of his Jedi officers, particularly for Skywalker, Ahsoka Tano, and Obi-Wan Kenobi. As such, Rex was hesitant to follow orders that put the Jedi in danger, especially those that came from the Jedi themselves, and was willing to sacrifice his life for the Jedi. He came to regard his clone brethren as his home and family, and he never forgot the many brothers whom he had lost to the war. His first loss of a unit, Torrent Company, at the Battle of Teth hardened him even further, and that he survived the ordeal was visible in his character from then on. During that campaign, Rex did not waver in his commitment to the mission, in spite of the possibility that the battle could be his last. While leading a squad of rookie soldiers against a full Separatist detachment for control of Rishi Station, he disregarded the odds against him, focusing only on his objective to retake the Republic base.

Despite witnessing enough of his comrades die to know that there was nothing glorious about war, Rex was unafraid to do his duty as a soldier of the Republic, even if it meant placing his own life and those of his troops in jeopardy. He made tough decisions calmly, would never back down from a fight, and was willing to fight to the last man if necessary; during the Second Battle of Geonosis, he even denounced a retreat as a cowardly tactic. Toughness aside, he viewed military service as an honor and greatly cared for the troops under his command, refusing to leave anyone behind if at all possible. He held the Separatist battle droids in contempt for all the damage that they had wrought on both him and his clone brethren, and cutting through droids on the battlefield frequently became an outlet for his rage and a way to avenge his fallen brothers. Despite his enmity with the Separatists, he assiduously lived by rules of engagement that transcended unwarranted behavior, regardless of provocation. After the loss of troopers Vere and Ince during a rescue mission, Rex pushed his anger to one side so that it would serve as fuel for the job at hand, intending to surrender to his feelings when in private. Sometimes, he even saw death as a method to assuage his belief that he had failed his men and to stop wondering how many more of them he would lose the next day. Yet he never gave up, watching over his troops throughout the pan-galactic conflict. Rex's care for his rookie 501st troopers on JanFathal was so substantial that he was surprised that his first instinct was not to look after Tano, whom he usually guided and mentored, but instead to take care of his men.

Individualism and Beliefs
A seasoned soldier born to fight for the Republic, Rex was not often given to softness or sentimentality of any kind. He possessed an unusual individualism as a clone trooper, encouraged early on in his career during his participation in Alpha-17's ARC training program. Though Rex took on a unique nickname, he opted to keep its origins to himself. Unlike most clone troopers, he even kept the name's origins private from his Jedi commanders. According to Skywalker, he was wound very tight as a rookie soldier, eager to carry out orders to the letter, but became less stiff as time progressed. He made a habit of reviewing mission parameters and objectives in his head prior to an operation, a trait that he shared with much of his clone brethren, since it had been drilled into them thousands of times during training on Kamino. He did not allow himself to be intimidated by his enemies, from battle droids to Dark Jedi like Asajj Ventress, though he did—at rare moments—acknowledge being afraid. Although he recognized that fear was necessary to understand the severity of a situation, he refused to let such feelings prevent him from doing his job. He even expressed humor in the direst situations, such as during the Battles of Christophsis and Teth, as he believed that humor had many uses. In some ways, he could not imagine how the Republic had survived in antebellum times, without himself and his clone brethren in the Grand Army providing support and security.

Rex relied on instinct, sometimes preferring to shoot first without bothering to ask questions. Like many clone troopers, he regarded his homeworld of Kamino with a degree of personal importance. As such, he fought proudly alongside Commander Cody and their brethren to repel a Confederate invasion of Kamino, even rallying a group of young clone cadets to join the fight for their homeworld. Rex did not always look to a soldier's rank for information and instead judged by experience, which outranked everything in his system of beliefs, even the seniority of his superiors. When addressing the rookie soldiers of Rishi Station, he used the derogatory "shinie" slang to underline their inexperience in combat. He was pleased when the rookies rose to the challenge and acquitted themselves well in their first battle; he placed a handprint of Rishi eel blood on Echo's armor to recognize the trooper's transition to a seasoned warrior, and he also honored Hevy's ultimate sacrifice to destroy Rishi Station. He and Cody succeeded in sharpening the rookie clones into an effective fighting force. Rex inducted both Echo and Fives into the 501st Legion for their valiant service, and he later promoted them to Advanced Recon Commandos for their courage and determination during the defense of Kamino. Rex even saw a bit of himself in the two troopers.

A disciplined captain, Rex was good at preserving a stoical front around his troops when facing setbacks. Even when deeply unsettled about the comm jammer situation at Kothlis, he was careful to maintain a focused outward attitude, to the point that Skywalker could only sense his unease through the Force. Although Rex was not easy to rattle, he was visibly startled when he overheard trooper Checkers complimenting his skills as an officer, and he snapped at Tano and Checkers to "stow the chatter" after that comment. As a commanding officer, Rex was efficient and thoughtful, and his decisions and conduct reflected his assiduity. He often stayed focused on the current situation by keeping himself busy, which he found easy to do on account of his countless day-to-day tasks as a soldier. He knew that over-preparation never hurt and kept his men ready for battle at all times. Opting for maximum situational awareness on the battlefield, Rex was not partial to the Republic's spacegoing navy. He preferred to have ground under his boots whenever possible, where he could use his natural senses to take in the environment around him, free of a starship's viewports. Even so, he learned to respect the willingness of civilian starship contractors to live or die by their workmanship's quality, since such workers often went space-side with assault craft in the war zone. He fell back on old-fashioned soldering whenever necessary, using hand signals to convey orders depending on the situation.

Rex learned what he could from the Republic's HoloNet News information bulletins, being used to absorbing information in that manner from his early Kaminoan flash training. He sometimes made judgments based on the contents of his training; for example, he respected diplomacy as a kind of fighting for which he lacked training. On the other hand, he saw fighting simply as a skill in which he was versed, not claiming to absolutely like it. Unlike some other officers in the Grand Army, he respected malformed clones like 99, whose strong spirit earned his admiration, and was greatly saddened when 99 died during the Battle of Kamino. Some of Rex's views were less open-minded, particularly as he encountered different cultures on his tour of duty. At times he did not pay much attention to history or culture; he initially could not understand the Lurmen of Maridun and their pacifistic choice to avoid fighting, attributing such behavior to a lack of pride. He also looked down on the Lorrdian militiamen during the battle for Ereesus, though he learned to trust and respect their aptitude for kinetic communication. When it was too late for the Lorrdians to return to their own base, he welcomed them to bunk with his own men. The experience additionally led him to form a close working relationship with one of the Lorrdian officers, Sollaw ap-Orwien. On Onderon, Rex embraced his leadership role in training the local rebels, treating them as he would the troops under his command. He did not hesitate to push them, impelling them to perform maneuvers like the soldiers they strove to become. When the time came to leave Onderon, Rex was impressed with the rebels' efforts.

Rex was tan-skinned and stood 1.83 meters tall, weighing eighty kilograms. He was versed in Galactic Basic Standard, the primary language of the Republic. Due to his naturally accelerated age, he was ten years old by the time of the Battle of Christophsis in 22 BBY, though his physical development was that of an older Human man. He paid considerable attention to his hairstyle, as he found hair under a helmet to be bothersome and annoying. As such, he regularly kept his naturally black hair shaved to a fine polish to prevent it from interfering with his concentration on the battlefield. Even so, he dyed his hair a light blond, his most obvious unique trait, and let it grow out to a certain extent on various occasions. He experimented with other hairstyles as well, briefly dying his hair blue after choosing to support the Bylluran Athletic bolo-ball team when it reached the finals. However, he eventually deemed his new hairstyle undignified and inappropriate for a commanding officer, and he shaved it off to better fit in with his black-haired troops. Rex had a small scar beneath his lower lip. He sometimes bared his allegedly perfect teeth in a feral smile when adrenalized for a coming engagement with the Separatists.

Effective Commander
A well-respected clone trooper captain, Rex viewed military service as an honor and acquitted himself as the leader of the 501st Legion. He projected an air of authority to his troops and earned their respect and obedience in that fashion. Leading by example, he saw the importance of being confident on the battlefield and motivating his men to fight for victory. To him, honor and service were the hallmarks of being a clone trooper. He trusted the men under his command and was a role model to them. He remained determined to achieve success in the face of danger, from frequently overwhelming enemy numbers to the life-threatening Blue Shadow Virus. Though he staked his life by the chain of command and did his best to honor superiors' orders, he also came to recognize the importance of a soldier's independence: He questioned orders instead of mindlessly obeying them and would adapt to shifting situations and plans as required.

Rex had several manners of etiquette as a commander that he strictly observed. He made a conscious effort to spend time getting to know all of his men on a personal level, and he consequently despised using the inconsiderate tally sensor to remember his charges' names because it was an admission that he could not tell his men apart from one another. He also valued his troops' privacy while not in combat. During the JanFathal operation, after the five rookie clones under his command opened up their own comlink channel, Rex avoided intruding on their conversation, even if they were cursing him for the recent loss of trooper Vere, and would have only overrode the frequency in an emergency. Outside of life-or-death situations, he abstained from barking out orders to his subordinates or superiors, believing that such conduct was improper.

In the absence of orders from superiors, Rex took matters into his own hands to ensure the survival of himself and his men. Despite generally being cautious and acting on certainty instead of hunches, he realized that in some situations there were no other options besides guesswork and improvisation. He was loyal to his men and genuinely cared for their well-being, for which he earned their admiration. All of Rex's traits in leadership were a testament to his effectiveness as a military leader, which was noticed by many of his colleagues, from troopers Checkers and Tup to Jedi General Pong Krell. Rex was well aware of his own talents as a leader and did his best to use them for the betterment of his men. His leadership skills were put to the ultimate test during the Battle of Umbara, where he was forced to balance the well-being of his troops with his commanding officer's strict orders. During that campaign, Rex found difficulty with uniting the 501st Legion under interim General Krell's leadership. Krell was focused on completing his mandates regardless of the cost, and he frequently employed strategies that the 501st perceived as reckless and costly. Though not afraid to speak out when he believed that he and his men were being treated inhumanely, Rex kept his men focused on their objectives and tried to set an example for his charges. He made an effort to respectfully cooperate with Krell despite the Jedi General's disagreeable behavior toward the clones.

Rex was tenacious in safeguarding his men's lives, even if that meant deviating from Krell's often reckless plans. At times he had more faith in his men than Krell did, trusting that Fives and Hardcase would be able to co-opt Umbaran starfighters from the nearby airbase—unlike Krell, who threatened to relieve Rex of his rank should he stray from the original assault plan. Rex was receptive to his subordinates' concerns and welfare in ways that Krell was not, requesting a respite for the battalion after a twelve-hour overland march. Whereas Krell simply activated one of his lightsabers to silence dissenters, Rex listened to his soldiers' grievances even when he did not agree, such as during their preparations to seize the Umbaran airbase. As time went on, he grew more open to defying Krell's orders in order to preserve his men's lives. After Fives, Jesse, and Hardcase refused to abandon their plan to eliminate the orbital Separatist supply ship, even though Krell had outright rejected their proposal, Rex did not attempt to restrain the three soldiers from leaving, but he also made it clear that he would not be able to save them from Krell's wrath once they were caught. Nevertheless, Rex covered up the trio's departure from Krell and also prevented Dogma and Tup from reporting their insubordination to Krell.

As the dissenting trio's commanding officer, Rex displayed a measure of responsibility for his subordinates' exploits, even though the decision to disobey orders had been theirs and not his. When Fives and Jesse returned, Rex tried to take the full blame and punishment for their actions, claiming that he had ordered them to disregard Krell's decree, though Fives returned the gesture by honorably reporting the truth of their disobedience to Krell. In the end, Rex's concern for his troops' welfare outshone his adherence to Krell's authority: He openly disobeyed Krell's subsequent orders to execute Fives and Jesse. He knew that if such punishment was rendered even once, then all of the 501st Legion could eventually face a similar demise, and he refused to let his men be subjected to fear of execution. He was horrified when Krell manipulated the 501st into attacking fellow clone troopers from the 212th Attack Battalion; the incident instilled in him the need for justice to prevent a recurrence of such an atrocity. He thus resolved to lead his men into the "uncharted territory" of arresting Krell for treason against the Republic. Given the mutinous nature of his proposal, Rex knew that he could not force his men into participating and gave them the option to opt out, though all of them except for Dogma supported his decision. For the entirety of the episode, Rex persevered in his commitment to his men, for whose safety he sought to detain Krell.

War of Loyalties
During the war, Rex swore to protect all Republic citizens from harm, including the ill-advised Chairman Chi Cho. At the Battle of Orto Plutonia, Rex knew that his men were risking their lives because of Cho's foolishness, but he nevertheless respected Cho's authority. Yet for all his wartime service, Rex's challenges were not only posed by his enemies. His loyalties and resolve were tested multiple times simply from his battlefield career. While he was aware that he and his clone brothers had been bred to fight for the Republic without a choice, he made the best of the situation. He knew that the politics and ideology of fighting were beyond his influence and instead focused on the day-to-day activities of looking out for his brothers in arms. When it came down to the nature of his commitment, it was not his relentless Kaminoan training or his loyalty to the Republic, but his dedication to his soldiers and Jedi officers that kept him in service. His compassion and selflessness as a commander was evidenced at Kothlis when, despite being severely injured, his first concern was for the welfare of his troops and comrades, not his own. His loyalty was so potent that even if he had not been born to serve, he could not imagine the prospect of abandoning his brothers and friends.

Over time, Rex learned to cope with his doubts about his origins as a clone trooper. Whenever the morality behind his manufactured birth was tested and his indoctrinated loyalty to the Jedi and the Republic challenged, he recalled that the men under his command depended on him to lead them—and that he would never be able to fight for the Republic if he questioned or scrutinized his birth's ethics. In that way, Rex put aside his insecurities for the greater good of the Republic. His strong loyalty to the Republic and the Jedi came into stark contrast with Sergeant Slick's hatred of the Jedi and betrayal of his comrades during the Battle of Christophsis. Rex had no respect for traitors like Slick and was visibly unsettled with Slick's perspective that the clone troopers were slaves to their Jedi commanders. Despite Slick's claim that he had been striking a blow for all clones, Rex drew the conclusion that the sergeant's actions—particularly putting his brothers' lives at risk by performing espionage for the Separatists—evidenced that he did not love and care for them as he so believed.

Rex's commitment to the Republic remained undeterred during his later encounter with the clone deserter Cut Lawquane, who had left the Grand Army relatively early on in the war. After first meeting Lawquane, Rex displayed a lack of patience for those who would abandon their duty, and he made his contempt for the deserter known. Once he had assumed a more respectful attitude toward Lawquane, Rex maintained that his beliefs had not been programmed into him, as Lawquane suggested, and that they were undeniably his own. He believed that his military service made him part of the most pivotal moment in the Republic's history and that the Grand Army's failure to defeat the Confederacy would mean the insurrection of an inconceivable evil. Despite disagreeing with Lawquane's outlook and disapproval of the war, Rex came to respect Lawquane as possessing a different type of loyalty—not to the Republic, but to his adopted family. Adding to his grudging but sincere regard for Lawquane was the deserter's brave effort to safeguard his family from invading droid commandos. When the time came to end his stay with Lawquane's family, Rex forwent his initial adamancy on turning in the fugitive Lawquane, opting not to report him as a deserter. He concluded that Lawquane was certainly not a coward and, before departing, politely refused his offer of a place at his farm.

As the Clone Wars continued, Rex feared that the Republic was beginning to view the clone troopers as a deindividualized, disposable army. He nevertheless upheld the mindset that the clone troopers' responsibility was to carry out and die for their missions when necessary. As he argued with Fives during the Battle of Umbara, that belief stemmed from his own code, not from the Kaminoans engineering him to think as such. In spite of his doubts about the clones' place in the Republic, he preserved his belief in the system for which he and his men were fighting. He held that the clone troopers were not independent of one another, that they were part of something larger than themselves, and it was thus not up to them to disobey orders in favor of strategies that they deemed more effective. Yet he was forced to draw the line when his loyalty to orders required that he see out General Pong Krell's decree to execute troopers Fives and Jesse for insubordination. Rex consequently realized that in some cases, it was necessary to make one's own decisions instead of blindly following orders like battle droids. Although he retained his loyalty to the Republic despite the incident with Krell, the Battle of Umbara left a lasting impression on his outlook as a clone trooper. In the face of so many casualties, he questioned the point of the war and wondered what would happen to the clones when the conflict ended, when they would no longer be needed as soldiers to fight the Clone Wars.

Steadfast Soldier
During the war, Rex became acquainted with a number of his brethren. He was good friends with Commander Cody, their friendship stemming from their mutual ARC training under Alpha-17. Their close relationship mirrored that of Skywalker and Kenobi—Rex's impulsiveness and superb instincts in battle won Cody's admiration, though Cody often worried that he put too much faith in them and rushed into danger too frequently. Still, Cody's penchant for procedure tempered Rex's impulsiveness, making them a good fit. After Rex fought alongside Sergeant Boomer countless times, Boomer became one of his trusted allies and close friends, as did Sergeant Coric of Torrent Company and Advanced Recon Commando Fives. Rex also shared an acquaintance with Commander Ponds and came to rely on fellow 501st trooper Denal for his instincts and expertise in combat.

Aboard Captain Gilad Pellaeon's Leveler, Rex found that he was comfortable with others who understood him as a fellow soldier, as opposed to Coruscant civilians who never would. Pellaeon described Rex as a solid, sensible chap who told very good jokes when not being the obedient solider around Skywalker. Cody admired Rex as a smart man, and Kenobi believed he always thought on his feet. Tup held his leadership in high regard, and Checkers saw him as one of the Republic's best commanding officers. Callista Masana interpreted Rex as a hands-on commander who did not want to look like he was letting others do the dirty work by not taking part in the reconnaissance of JanFathal's capital of Athar.

Serving under Skywalker
Serving closely with Skywalker throughout the Clone Wars, Rex absorbed much from the Jedi General's style of leadership and daring improvisation. He learned to think on his feet, to consider methods outside of the regulation manuals, and to never surrender or let seemingly overwhelming odds dissuade him on the battlefield. He adopted Skywalker's inclination for unorthodox combat tactics, which often yielded spectacular results against the enemy. Rex was as headstrong and as brave as Skywalker, with full confidence in his own abilities, and it was the duo's similar lack of "by-the-book" methods that made them such an excellent team. He shared Skywalker's aggression, free thought, and occasional recklessness—a combination that got them both in and out of trouble. From his service with Jedi officers on the war front, Rex regarded them as figures of authority and learned to both respect and never doubt their resolve or powers. In turn, the Republic's Jedi Generals came to rely on him on the front lines, and his performance as an honorable military leader effected him becoming well-respected by Jedi officers and clone troopers alike. However, he sometimes disapproved of the preference to debating over fighting that some Jedi possessed. On the other hand, Skywalker matched Rex in bravery, aggression, and decisiveness, and the general's "soldiery" traits helped Rex to form something of a friendship with him.

Rex worked closely with Skywalker on the battlefield, offering thought-out suggestions about strategy as he saw fit, and respected Skywalker because he put himself on the line with his troops. Even though Skywalker at times maintained an authoritative demeanor of command, Rex did not resent such conduct on his part, knowing that respecting the chain of command was an integral component of an officer's performance. Like the rest of the 501st's Torrent Company, he was truly devoted to Skywalker and was proud of the trust that his general invested in him. Skywalker in turn thought highly of Rex, believing him to be the finest and most loyal trooper with whom he had worked, and introduced him as such to General Pong Krell. As a soldier, Rex was loyal to Skywalker not only on the battlefield, but also on a personal level. When Skywalker was away during Leveler's shakedown cruise, Rex kept him regularly apprised with the situation to prevent his general from being caught out of the loop. In addition, when Skywalker pursued fugitives Rako Hardeen, Cad Bane, and Moralo Eval to Nal Hutta without the consent of the Jedi High Council, Rex made an effort to conceal his general's unauthorized undertaking from Mace Windu.

Rex was not upset when Skywalker was unable to aid Torrent Company during the Battle of Teth. True to his belief that the mission always came first, he understood his general's mandate to return Rotta the Huttlet to Tatooine. Furthermore, he looked up to Skywalker as a role model; when serving away from his general, he would sometimes consider, as he did more than once during the battle on Ereesus, what Skywalker would have done in his position to ensure success. The time that Rex spent with Skywalker was such that he even became aware that his general had feelings for Senator Padmé Amidala, though he was unaware of the full extent of their attachment. On some occasions, he pitied Skywalker, who was often prone to guilt and regret when forced to prioritize other assignments over serving alongside his captain. He became used to Skywalker's personal style of command and worked well with his Jedi General.

Besides his friendship with Skywalker, Rex was acquainted with Obi-Wan Kenobi, Skywalker's own former Master. Rex made it a goal to procure a laugh from Kenobi on the battlefield with his sarcastic jokes, though he did not have much success. In spite of his respect for his Jedi officers, Rex did not share all of their beliefs, particularly regarding the Jedi Code. Whereas Kenobi restrained himself from taking the life of the unarmed Keeper Agruss despite the Zygerrian's crimes as a slaver, Rex had no such reservations and acted decisively, killing the keeper.

Mentor to Ahsoka
After meeting Ahsoka Tano on Christophsis, Rex admired her spirit, though he was concerned with her initial naivety and arrogance toward her commanders, particularly Skywalker. Once the captain and Padawan reached an understanding of each other, they began to form a strong bond and supported each other as the galaxy-shaking war progressed. Rex often addressed Tano as "kid" in lieu of a more formal title. As Tano's teacher in military matters when Skywalker was absent, Rex preferred to train by example, and it was in that manner that he often instructed Tano. Among his lessons for her was that smart remarks were unhelpful and disruptive in times of protocol, especially when they were directed at her Master. They came to respect each other, and he earned her trust with her life. He defended her proficiency from others who expressed hesitancy with her competence, including fellow officers like Gilad Pellaeon and Wilhuff Tarkin. In addition, Rex encouraged Skywalker himself to maintain his faith in his Padawan during a confrontation with Asajj Ventress on Taronda. Rex's attitude toward Tano was such that Skywalker came to trust him with her, and Skywalker additionally recognized that some of the Padawan's lessons were better learned from the captain instead of himself.

Rex helped Tano through several tough situations, including on Maridun, where their team was forced to find medical attention for a grievously wounded Skywalker, and at JanFathal, when their encounter with the Altisian Jedi challenged her beliefs in the Jedi Code. Rex also guided Tano in her first command position at Ryloth, even though she expressed insecurity with the role. Although he was skilled in strategy and carefully identified the obstacles that hindered Tano's plan to break the Separatist blockade of Ryloth, he remained respectful toward her and did not outright criticize her proposed tactic. He mentored her in leadership as time went on, instilling in her the importance of inspiring one's troops and leading by example on the battlefield, no matter the situation. On occasions when Tano was unable to voice her full concerns to him because of security or protocol surrounding certain assignments, Rex fully understood the reasons behind her withholding of confidential information, and he did not take it personally. Although in some cases he knew when she was concealing her fears from him, including those about her Master's life, he did not criticize her for being afraid; instead, he supported her in what ways he could.

During the search for the fugitive Tano at the Republic military base, Rex refused to believe that she had slaughtered three clone troopers while escaping, even though the lightsaber cuts on the corpses indicated that she was responsible. Nevertheless, he was forced to set aside his personal beliefs in favor of the evidence at hand, stating in a following all-points bulletin that Tano had killed the three soldiers. Rex's instincts were later upheld when it was revealed that Barriss Offee had committed all the crimes for which Tano had been accused.

The Trouble with Krell
By the time of the Battle of Umbara, Rex had become used to Skywalker's more personal style of command. He thus came into conflict with the 501st Legion's interim Jedi General on Umbara, Pong Krell, a hard leader who strictly adhered to the chain of command. Rex initially respected Krell for his impressive military record, but he found that Krell was difficult to work with because of his apparent lack of regard for clone troopers—Krell preferred to address them by their numerical designations instead of their individually chosen names, with which Rex took issue. Although he did his best to cooperate with Krell, he found that the Jedi Master rarely responded positively to suggestions as Skywalker did. Furthermore, he frequently viewed Krell's methods as flawed and reckless, since they often involved head-on assaults with high casualties. Even after Krell forced an uncooperative Fives to stand down by igniting his lightsaber, Rex firmly stood his ground against the Jedi General. He defended his troops' well-being and removed his helmet to speak to Krell face-to-face, asserting that the clones were men rather than faceless, rank-and-file soldiers. Though his tenacity and loyalty to his subordinates won Krell's respect, Rex still failed to see eye-to-eye with Krell as the Umbara campaign continued.

Over time, Rex became more willing to disobey Krell's orders. During the battle to reach the Umbaran airbase, Rex developed a secondary plan to have Fives and Hardcase seize two starfighters from the enemy outpost to use against the Umbaran mobile heavy cannons. Though Krell did not approve of his strategy and even threatened to relieve him of duty for insubordination, Rex allowed Fives and Hardcase to carry out their stealth incursion. When Krell claimed that Rex had yet to understand that copious casualties were the price of victory, the captain's respect for Krell waned, and he agreed with Fives that it was Krell who would never understand the clones' sacrifices. After Fives, Hardcase, and Jesse slipped away on their illegal plan to target the Separatist supply ship in orbit of Umbara, Rex covered for them during their absence. He outright lied to Krell, providing a fake cover story that he had authorized the trio's use of the locked-down Umbaran starfighters and kept the Jedi General in the dark about the nature of their departure. Ultimately, he overtly defied Krell's orders to execute Jesse and Fives for their insubordination, and his respect for Krell eroded even further as he refused to be intimidated by the general's threats for retribution.

Rex began to question Krell's authority as well as his sanity, even suspecting that the Jedi Master had betrayed the Republic, and his suspicions were proven correct when the general turned the clone troopers against one another on the battlefield. He was appalled at Krell's crimes against his soldiers, especially since Krell was a Jedi Master. From that point onward, he resolved to treat Krell as a traitor, risking charges of mutiny to arrest the Jedi General for treason against the Republic. Rex deplored Krell's fall from the ideals of the Republic and his quest to become Count Dooku's new apprentice. With the imminent danger of the Umbaran militia advancing on the airfield, Rex reluctantly agreed with Fives, Jesse, and Tup that Krell needed to be executed before he could convey the Republic intelligence in his possession to the Confederacy. When about to shoot Krell, Rex remained undeterred by his taunts about being in a position of power. Yet for all the casualties that Krell had caused, Rex was unwilling to pull the trigger on an unarmed Jedi, and Dogma instead terminated Krell.

Skills and Abilities
Rex's gifts in critical thinking and leading his brethren into battle reached the attention of the Kaminoan cloners, and he thus underwent command training and intensive programmed learning on Kamino. Further ARC training under Alpha-17 sharpened him into a cunning and lethal soldier. As an expert in multiple forms of combat, Rex was skilled in armed and unarmed fighting. He was knowledgeable in the use of a jetpack, taking squads through the most difficult of flight paths. He was additionally well-versed in reconnaissance and military tactics and was capable of leading specialty clone trooper units in various operations when the need arose. His abilities were such that he came to be considered one of the best soldiers in the Grand Army. Rex valued being an accurate shot with a blaster and became proficient in marksmanship. He was able to hit both fast-moving targets—such as a flying fuel cell on Skytop Station or a Single Trooper Aerial Platform on Lola Sayu—and distanced marks alike, eliminating a gun emplacement on Geonosis from several hundred meters away.

Like any good soldier, Rex knew his weapons and swore by his armor and gear, but he also recognized that equipment alone could not win a battle—a soldier's greatest tool was his mind. Relying on intelligence over weaponry, he combined a commando's gift of improvisation with the toughness of an infantryman. Having been trained to resist interrogation as a prisoner of war, he was adept in mental resistance and was able to shield himself from a Force mind trick performed by the Dark Acolyte Asajj Ventress, due in part to his strong will and focus. He was relentless in using his abilities and equipment against his adversaries, whether they were Separatist droids on Ryloth or aggressive Talz warriors on Orto Plutonia, the latter of whom he faced with steely determination. He had a fast reaction time even when not in combat: He responded instantly with his blaster to the appearance of a Rishi eel on the Rishi moon, killing the predator with a single shot to the eye. He recognized the danger of hesitating in battle, even for a split second, and resolved to eliminate all of the enemies in his path before they could gain the upper hand. As Skywalker noted during the Battle of Christophsis, he did so without even having to think about his maneuvers.

Rex was able to hold his own against the larger units within the Separatist Droid Army, including octuptarra magna tri-droids and heavily armed Vulture droid starfighters. Though he dreaded the latter the most of all of the Separatists' combat droid models, he stood his ground against them. He was quite strong and was able to lift the injured Chairman Chi Cho without aid. He was also able to escape defeat at the hands of a menacing assassin probe aboard the Coronet by grabbing the attacking droid's pincers before they impaled him; he then managed to kick the large droid off himself. Against ruthless winds and menacing electro-mines on Lola Sayu, he was able to free-climb the cliff to an entry point to the Citadel. Despite having a temporarily paralyzed arm during the Battle of Saleucami, Rex was able to roll and fight in blaster combat against several droid commandos.

Phase I Armor and Weaponry
During the first months of the war, Rex used a suit of plastoid Phase I clone trooper armor that was customized with the white and blue of the 501st Legion. His polarized T-visor helmet sported Mandalorian Jaig eyes as battle honors and was equipped with a fold-down rangefinder scope that included a night vision filter. For supplemental head gear, he used a visor with an inbuilt telemetry system and a pair of removable spot lamps that boasted a viewing range of forty feet. His helmet systems included infrared vision; an array of sensors; an internal comlink; visual and auditory buffers; and a heads-up display with thermal imaging and biosign indicators.

To complement his body armor, Rex sported a traditional kama half kilt, constructed out of leather and thick anti-blast armor, to repel low-flying shrapnel and debris. He also wore over his left shoulder a semi-blue pauldron armor plate, which was reserved for clone officers. It was punctured through the chest plate by an enemy droid sniper during the Battle of Saleucami. Besides boots with magnetic gripsoles, Rex used a variety of other tools: a vibroblade in one of his gauntlets; a wrist comlink for his left gauntlet; a medpac and high-calorie dry rations in his utility belt; and a rappel line with a winch control motor for climbing during combat. His armor suit had an airtight seal and a limited oxygen supply, which allowed him to survive in the vacuum of space for brief intervals, such as during the Battle of Devaron. For some operations, he wore standard-issue white clone trooper armor. While on Orto Plutonia, he donned cold-weather armor—including a thermal suit and rebreather hood, the latter of which was decorated with his Jaig eyes—for protection from the cold. Although necessary for surviving Orto Plutonia's hazardous conditions, the extra gear dangerously limited his movements in battle.

Being skilled in marksmanship, Rex never underestimated the capabilities of a good old-fashioned blaster and used a variety of weapons in combat. He preferred to wield a pair of DC-17 hand blasters for their speed, a trait that he shared with the dual pistol–using Jango Fett, the bounty hunter from whom he was cloned. Rex cut his blasters' holsters at his waist to be able to draw them more quickly. Although his two DC-17s were his signature choice of weaponry, he sometimes used a DC-15S or a DC-15A blaster rifle. On JanFathal, he used a DC-15 with a customized detonite grenade launcher attachment. He also used a grappling hook extension as required. As thanks for helping to contain the Blue Shadow Virus on Naboo, Rex received a set of modified DC-17s from Theed Arms. The pistols, dubbed the "Vigilance" and "Negotiator," were specially plated with metallic chromium, a prerogative of the Naboo royalty. When it came to heavy weaponry, Rex was capable with using missile launchers like the RPS-6 rocket launcher, which he employed against enemy ground vehicles.

Rex carried a set of electrobinoculars for expanding his viewing range on the battlefield. When the situation called for it, he used a JT-12 jetpack and accompanying flight equipment, as he possessed expertise with the gear. He used a space combat propulsion pack to boost his jetpack's range for high elevations, for as far reaches as realspace. While away from the front lines, Rex made himself comfortable with black fatigues instead of his usual hefty armor.

Transition to Phase II
When the Republic began to have its clone soldiers transition to the Phase II set of clone trooper armor, Rex did not particularly care for the new equipment, as he believed that it was prefabricated and too disposable. He did not immediately switch over to Phase II, but when he did, he developed his own unique version of Phase II armor, combining elements of his old Phase I suit and the latest Phase II technology into a hybrid of both armor sets. Salvaging the middle portion of his old Phase I helmet, including his rangefinder scope and original T-visor, he welded them together with the new Phase II helmet's upgraded breath filters and voice output annunciator. He did the same for portions of his chest plates, and the resulting weld marks became another of his armor suit's distinctions.

Although Rex modified his helmet, he retained his Jaig eyes from his Phase I suit. Aside from a redesigned pauldron with an ammunition pack and an updated wrist comlink that he transferred to his right arm, he continued to use the rest of his Phase I equipment, including his kama, utility belt, removable spot lamps, and quick-draw blaster holsters. Though he still carried electrobinoculars, he began to use a polarized macrobinoculars attachment with his helmet. He even began to engrave tally marks into his helmet, gauntlet, and forearm and leg plates to record his growing number of kills. In addition, he started carrying an Imagecaster holoprojector. He used a JT-12 jetpack with his Phase II armor as required, as well as a SCUBA trooper mask, decorated with his Jaig eyes and blue 501st markings, for underwater combat. For space-walking, he used breathmask survival gear, which consisted of a back-mounted pack with breathing tubes that connected to both of his helmet's breath filters.

For the assignment of helping the Jedi train the Onderon rebels, Rex adopted a new suit of armor to avoid using his usual, distinguishable set of 501st white and blue. The result was a set of black fatigues with a limited amount of equipment, including a jetpack for the deployment into the Onderonian jungle. Although he chose a different helmet with a visor and goggles, he made sure to have a rangefinder for his helmet and also sported his Jaig eyes on his chest plate.