Rex

"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

CT-7567, nicknamed "Rex," was a veteran clone trooper captain who oversaw Torrent Company of the Grand Army of the Republic's famed 501st Legion during the Clone Wars. 15 years after the end of the Clone Wars, Rex was still alive and was living in a modified AT-TE on Seelos with Commander  Gregor and Commander Wolffe.

Biography
CT-7567, later known as "Rex", was a clone of the bounty hunter Jango Fett created and trained on Kamino. He eventually was made a captain.

The Clone Wars
Rex fought at the Battle of Geonosis against the Separatists' forces. He survived the battle and continued to serve in the army to protect the Republic's citizens as part of his loyalty to the Republic.

Rex was then assigned to Jedi General Anakin Skywalker as his 2nd in command. He was then given command of Torrent Company of the 501st Legion. Rex was eager to follow orders but became less wound tight in time. He also worked alongside Commander Cody at battles such as Tibrin. He also served alongside Jedi General Obi-Wan Kenobi.

Battle of Christophsis
Some time after the Battle of Geonosis, Rex accompanied Skywalker, Kenobi, Cody and the rest of the Republic forces in their effort to liberate Christophsis from the Confederate forces under General Whorm Loathsom and Dooku's assassin, Asajj Ventress. The Captain took part in setting up an ambush on the approaching Separatist forces, but watched on as Kenobi and Cody were ambushed themselves. Skywalker rushed to his master's aid, with Rex and his men alongside. Fleeing to the rooftop, they held off the battle droids until evac arrived in the form of a gunship, with clone trooper Gus removing the commanding tactical droid's head before departing. Rex then assisted Cody in performing a robolobotomy on the droid's head, discovering that it contained all of their intelligence. Surmising that this meant there was a spy in their midst, Generals Skywalker and Kenobi departed to investigate the Confederate headquarters, hoping this would reveal the spy's identity. Rex and Cody were instructed to conduct their own search at the Republic base.

As they were leaving the command center, Cody noticed that someone had left their comlink on; their entire conversation had just been broadcast to the Separatist spy. Rex spotted someone in the corridor, and he and Cody gave chase. However, they lost him in the busy mess hall. The spy, they now realized, was a clone. Unable to reach the Jedi as a result of blocked communications, Rex had R2-D2 analyze the communication history to see if anyone had sent out any unauthorized transmissions. He noticed irregular wavelengths that were too low and infrequent to be detected normally, wavelengths that were coming from Sergeant Slick's barracks. They proceeded to question Slick's men, all of whom had an alibi except Chopper, who lies about collecting battle droid fingers. However, Slick slips when he reveals that he knew the Jedi were gone. Slick escapes, and manages to evade Rex and Cody while also blowing up the nearby weapons depot as well as many of the gunships and AT-TE's.

Following a lead from Gus and Chopper, Rex and Cody venture back to the command center. There, they notice boot prints that trail up towards the vents. Without a word between the two of them, Rex and Cody devise a trap; Rex pretends to leave the room, while Cody stands with his back to Slick's hiding spot as well as his gun. Slick slides out of the vents and points the gun at the back of Cody's head, but is shocked to learn that the gun is empty; Cody took the clip out beforehand. After a short fist fight, Rex and Cody are able to subdue Slick, just as the Jedi return from their fruitless trip to the Separatist headquarters. Skywalker verbally rebukes Slick for placing his brothers at risk, and Slick replies with a venomous attack on the Jedi's enslavement of his brothers, the clones. Despite Slick scorching the entire weapons depot, Rex and Cody note that they were able to save the heavy cannons.

As Loathsom's droid army moved in on their positions, Rex and his men accompanied Skywalker as he took on the tri-droids. Soon after, Rex met Skywalker's new apprentice, Ahsoka Tano, laughing as she calls Skywalker "Skyguy". He proceeded to show her the ropes as a commanding officer, offering her advice and valuable leadership experience. He also stated that while she may outrank him, it's experience that outranks everything. Before long, Rex spotted the Deflector shield being used by the incoming Confederate forces, rendering their cannons useless.

After conferring with Kenobi, Cody and Rex, Skywalker and Tano left to destroy the deflector shield, while Rex assisted Kenobi in holding back the droids before they were able to destroy the heavy cannons. As Kenobi lead a charge against the droids, Rex and his men drew the droids into the buildings, making the fight more manageable for the clones. Despite this, most of Rex's unit was wiped out, and he was soon ordered to pull back his forces in order to protect the cannons. As Kenobi delayed Loathsom with a drawn-out surrender, Rex noticed the shield drop and ordered the cannons to finish off the tanks, ending the battle.

Battle of Teth
Rex, alongside Skywalker, Tano, and the rest of Torrent Company then went to Teth to rescue Jabba the Hutt's son, Rotta. After landing Rex and the rest then used their ascension cable to climb the cliff's below the Monastery underfire from two droid battalions. After making the climb, Rex and his men secured the Monastery. After Skywalker and Tano found Jabba's son, Vulture droids attacked as two Separatist landing crafts landed, deploying more battle droids under the command of Ventress. Rex and his men then retreated into the monastery.

Rex and his men then stayed behind to keep the battle droids busy. After Ventress cut the door's lock, Rex and his men fought the droids. After the droids subdued his men, Rex then picked up his pistol and tried to shoot Ventress. Rex was then disarmed and was then force strangled by Ventress, demanding the location of Skywalker. Rex refused, but Ventress was able to use a mind trick to make him contact Skywalker. However, Rex was able to alert Skywalker that Ventress was coming.

When Rex was contacted by Skywalker, a battle droid came over. Rex then punched and took it's weapon. Rex and his troops then fought the droids guarding them. As they were surrounded, help arrived from Kenobi and Cody. Rex was then able to destroy a spider droid with detonator. Rex then told Skywalker they could take care themselves and that the mission came first. Rex then went with Kenobi, Yoda, and Cody to pick up Skywalker and his apprentice from Jabba's palace on Tatooine.

Skirmish on the Rishi moon
Rex then went with Cody on a inspection tour using Obex. After inspecting of the tracking station at Pastil, Rex and Cody then went to the Rishi moon station. En route, Rex contacted station. Rex noticed something odd about the trooper's reluctance to their inspection. After landing, Rex and Cody were greeted by a trooper who said that the base was fine and asked them to leave. Rex then demanded to be taken to the sergeant command, noticing the trooper saying "roger, roger". Rex and Cody then saw a droid attack flare, and he drew his pistol and shot the trooper. Rex then saw that it was a BX-series droid commando. They then came under attack by more commando droids that cut them off from the ''Obex. ''Rex and Cody then jumped off the platform as the commando droids threw detonators at them. They then used their ascension cables to climb down.

They then met the surviving troopers, Fives, Hevy, and Echo. After removing their helmets, they came under attack by a Rishi eel, but Rex was able to shoot in the eye. Rex then marked Echo with the eel's blood and told them to follow him and Cody. Rex then pretended to be malfunctioning commando droid by using a head from one and saying "roger, roger". After the droids opened the door, Rex, Cody and the rest of the clones then stormed the command center, taking out the commando droids. They then spotted a Confederate fleet approaching, but were unable to contact the Republic. When landing craft came down, Rex said they would blow up the station so that the Republic fleet would arrive to investigate. Rex then rigged the gas detonators as Cody and others held up the battle droids. However, the remote detonator was not working. Rex and the others then left while Hevy fixed the detonator. However, Hevy refused to leave intending to sett the gas off manually. Rex and the others then tried to go back for him but Hevy blew up the station. Rex and the others were rescued by a gunship. Following Echo and Fives medal acceptance, Rex accepted them into the 501st.

Battle at Bothawui & Skytop Station
After the fall of Falleen, Rex, Skywalker, Tano and their fleet were sent to protect Bothawui. Rex and the fleet's AT-TEs were then deployed on the asteroids surrounding Bothawui. As Grievous moved in to attack Skywalker's fleet, Rex and the AT-TE opened fire on the rear of Grievous's fleet. Rex then saved Skywalker when his fighter was damaged. Rex then stayed with Ahsoka as Skywalker searched for Grievous's spy station. Rex and Ahsoka then detected Skywalker's tracking signal. The two of them then took the Twilight and rescued Skywalker from Grievous's forces.

Rex then assisted Skywalker in his search for the listening post. After receiving a message from R2, Rex, Denal, and his squad then accompanied Skywalker in destroying the station in the Ruusan system. Rex also carried R3-S6 down to the station. Rex, Ahsoka, R3 and the rest squad were then sent to destroy the station's reactors while Skywalker searched for R2. However, R3 slowed them down leading to confrontation between super battle droids. They were able to subdue them the droids. However, Rex, Ahsoka and the squad were then confronted by General Grievous. Rex and his squad tried to shoot but all were killed except for Rex and Denal. As Grievous was about to be killed, he was saved by Ahsoka. Rex and Denal were then ordered by Ahsoka to complete their mission without her. Rex and Denal were then able to rig the reactors and rendezvous with Skywalker and the Twilight in the landing bay. However, Rex and Skywalker then realized that R3 was a spy when he summoned super battle droids and vulture droids to attack them. Rex then destroyed the reactors and they were then joined by Ahsoka and made their escaped with Skywalker rescuing R2.

Battle above Quell
Later during the conflict, Rex joined Skywalker, Tano, Admiral Wullf Yularen, and several other clone troopers to the planet Quell, where Jedi General Aayla Secura and her clone commander, Bly, fought against a Separatist opposition. With Secura's cruiser damaged, the Republic forces were in a hurry. After breaking through a line of rocket super battle droids, they landed on Secura's ship, where Skywalker was injured in an explosion on the exploding ship. With fellow troopers Cameron, Flash, and Lucky, Rex, Tano, Secura, Bly, and Skywalker escaped on a transport vessel. However, they were then hit and entered hyperspace. They were then forced to crash land on Maridun.

Rex then stayed behind with Skywalker while Secura, Bly, Ahsoka, and the other troopers went to look for help. Rex then fought against the Mastiff phalones alongside Skywalker until Bly, Ahsoka, and Lurmen healer Wag Too came to his aid.

Defense of Maridun
Rex then watched for any spacecraft hoping for rescue. Rex then spotted a Confederate landing ship coming toward the village. He informed Bly of this and then made their escape from the village before the battle droids arrived. Rex and the others then planned to steal a shuttle, but were then spotted by a recon droid. They then pursued it until Secura destroyed. Rex and the others then watched as General Lok Durd prepared to test his weapon. Rex went with Bly to get a closer look at the weapon. Rex and Bly then ran to avoid the weapon's shockwave using their grapnel lines.

After Durd left, Rex worked with Bly and Skywalker to infiltrate Durd's base, where they were able to steal a shuttle and shield generators. Rex and the group then returned to the village, where Skywalker, Bly and him built a wall to withstand, much too Tee Watt Kaa's disapproval. Rex and Bly then activated the shield as the Defoliator Tank fired it's weapon. Rex and the others then stood their ground until the droids breached the shields and destroyed. Luckily, Rex, Bly and the others then had help from the Lurmen and were able to subdue and capture Durd and Pune Zignat. As Rex was taking Durd and Zignat, Republic cruisers then arrived to rescue them.

Battle of Orto Plutonia
Rex then accompanied Generals Kenobi, Skywalker, Pantoran Senator Riyo Chuchi and Chairman Chi Cho to Orto Plutonia. There, they investigated Gild Station to ascertain what happened to the troopers. Rex and the Jedi then went to Confederate outpost, where they saw a hologram of a creature attack the battle droids. Rex then returned to the station, where he and his troops waited for the Jedi's return. Rex and his troops then went with the Jedi, Chairman Cho, and Senator Chuchi to speak with the Talz Chief, Thi-Sen at the Confederate base. After the meeting was over, Rex was then charged with protecting the Chairman when he decided to attack the Talz. Rex, his troopers, Cho, and his guards were then surrounded by the Talz. When Cho was mortally wounded, Rex and his men retreated, carrying the Chairman with him. Rex then formed a defense line near a cliff and held out until Skywalker, Kenobi, Chuchi and the rest of the troops arrived.

Raid on Vindi's Lab
Rex was then sent to Naboo to assist Skywalker and Kenobi to stop Confederate scientist, Dr. Nuvo Vindi, from deploying bombs laden with the Blue Shadow Virus. Rex then fought alongside Commander Tano in fighting their way through Vindi's lab. They were able to stop Vindi's droid, LEP-86C8, from unleashing the Virus.

However, LEP-86C8 was able to steal a vial and trigger one of the bombs, contaminating the labs. Though Rex and his troopers were able to seal the lab, they were infected with the Virus. Alongside Senator Amidala and Representative Binks, they were able to destroy all the droids, they were slowly being killed off by the virus. Fortunately, Skywalker and Kenobi were able to administer a cure to them and save them.

First Battle of Felucia
Rex, alongside Cody, Skywalker, Tano, and Kenobi was then sent to Felucia. However, their forces were then surrounded. Luckily, they were then rescued by General Koon's forces.

Battle of Devaron
Rex then went with Skywalker and Tano to Devaron to stop Bane from taking the Kyber memory crystal from Master Bolla Ropal. Rex then gathered three brigades to board Bane's ship. Rex then approved of Skywalker's idea of using the ATTEs to board Bane's ship. Rex, Skywalker, Tano and their troops were successful in boarding the ship, though they did not save Master Ropal in time. Rex and the others then found Bane on the gun deck. Rex and his then fought the battle droids while Skywalker and Tano pursued Bane. Rex and his men then secured a shuttle and waited for Skywalker and Tano to return. When they returned, Rex watched as Denal shot Bane.

After returning to the Resolute, one of the Rex's men then spotted blood. Rex then told Skywalker that it was not of his men's blood. Rex and Skywalker then realized that Denal was actually Bane, who then made his escape.

2nd Battle of Geonosis
Rex then fought with Skywalker, Tano, and his troops when the Republic returned to Geonosis. After Skywalker's gunship were shot down, Rex and the others continued towards Kenobi's position on foot. Rex then assisted Skywalker and Tano in taking out a droid fortress blocking their path. After the fortress was destroyed, Rex, Skywalker, Mundi, Tano and the rest of their forces were able to rendezvous with Kenobi and Cody.

Rex then fought alongside, Skywalker, Unduli, Gree and their troops to distract Poggle's forces while Tano and Offee infiltrated the droid foundry. At first, they were able to drive back the battle-droids. However, Rex, Gree and their troops were forced to fall back when Poggle sent in Super tanks to finish them off. After the foundry was destroyed, Rex brought in their tanks and gunships to search for Tano and Offee. Rex then saw Tano and Offee leave to recuperate.

Rex then accompanied Skywalker, Kenobi, Undili and Mundi to deliver Poggle to Coruscant. Rex then stayed alert when Tano and Offee failed to check in time. Rex was then able to contact Tano and informed Skywalker of this.

Battle of Saleucami
Rex then accompanied Skywalker and Master Gallia to the Saleucami system to rescue Master Eeth Koth from General Grievous. Despite rescuing Master Koth, Grievous escaped to the surface of Saleucami. Rex then went General Kenobi and Cody to track him down.

Rex and several of his troopers investigated the remains of Grievous' landing ship. Rex then took Jesse, Hardcase, and Kix through the wet lands to find Grievous. However, Rex was then shot by commando droid sniper. He survived, but had to be left behind at a farm to recover. Rex then discovered that the owner of the farm was clone deserter named Cut Lawquane. At first, Rex was disgusted by Lawquane's lack of commitment to the Republic. Despite this, Rex accepted his children's invitation to dinner. Rex then talked about how he would stay in the Army no matter. Rex was then told how Cut left the army after his team had been shot down, killed off, and then he ran. Rex and Cut's family came under attack by commando droids. Together, Rex and Cut were able to destroy all the droids, with Cut rescuing Rex from one. The following day, Rex decided not to turn him, seeing him as not a coward. He then rejoined Kenobi's forces.

Skirmish on the Coronet
Following Kenobi's investigation on Mandalore, Rex, Cody, Skywalker and several troopers were requested to protect the Duchess Satine Kryze and her entourage from the Death Watch and the Separatists aboard the Coronet.

Rex, Cody and their troops were then briefed on the importance of protecting the Duchess. They then stayed in the cargo bay. Rex then saw that R2 was spooked by something and that 2 of his troopers were missing. Rex, alongside Skywalker, then found an open container. They then continued the search until Skywalker was attacked by a Assassin probe. Rex and Cody were then able to take it out. However, they then came under attack by Probe killers. After defeating them, Rex and Cody continue their search taking out the last probe killer. Rex was then attacked by the last assassin probe but was able to hold off it's claws before Skywalker took it out. Rex then fought off super battle droids boarding the Coronet alongside Cody, their troopers, and the Mandalorian royal guards.

Battle of Kamino
Rex, Cody and their troopers then returned to his home world of Kamino when a message between Grievous and Ventress was discovered. Rex and Cody then joined Fives, Echo, 99 and several young cadets in the barracks. Together, they fought off the battle droids, but 99 was then killed. Following the battle, Rex then promoted Echo and Fives to ARC trooper.

Battle of Lola Sayu
When Master Piell was captured, Rex alongside Cody, Fives, Echo, Kenobi and Skywalker attended a briefing held by Plo Koon for a mission to rescue Piell from the Citadel on Lola Sayu, where he was imprisoned by the Separatists. In order to get on the planet undetected, Skywalker had the entire rescue team, including Rex, carbon-frozen. The frozen team was smuggled by R2-D2 and some reprogrammed battle droids in a stolen Separatist shuttle. This tactic succesfully fooled the life-form scanners of the blockade around the planet and its crew and the droids landed the shuttle in a cave close to the Citadel prison. After landing, Rex and the others were unfrozen, only to discover that Ahsoka Tano had secretly joined the team, despite having received orders not to do so. Since there was no other option, Ahsoka came along and the team began the mission.

In order to get in the facility the team had to free climb a wall covered with electro mines. This went well until a clone trooper stepped on a loose rock and fell straight into a mine, alerting the prison crew of the team's presence. On the way to Piell's cell the team had to evade several boobytraps, one killing another clone trooper. The team made it to Piell's cell and destroyed the droids that were guarding Piell, with Rex taking care of the interrogator droid. On the way to rescue Piell's the group was located by the Citadel's warden, Osi Sobeck, who activated a large magnet in the ceiling of the hall that pulled all the team's weapons away, as well as Skywalker, due to his Cybernetic arm. The team was surrounded by droids. Skywalker, being attached to the magnet, reclaimed his lightsaber and destroyed the magnet, allowing the team to reclaim their weapons and destroy the droids. Rex shot a survaillance camera, much to Sobeck's frustration, before moving along. After retrieving Piell's officers the group decided to split up in two groups while escaping the facility, as both Piell and his captain, Tarkin, knew half of vital hyperspace coordinates, called Nexus Route. By splitting them up during the escape it would be more difficult for the Separatist to get the full information. Rex joined the group consisting of Skywalker, Tano, Tarkin, Echo, Fives and two rescued clones. While Kenobi and the other group wreacked havoc on the upper levels, Rex and his group escaped the tower into a series of tunnels on the lower levels.

Rex and the others then made their way through tunnels fighting off the super battle droids and commando droids. He also defended Ahsoka when Tarkin questioned her experience. They were then able to meet up with Kenobi's and Piell's team at the airfield. However, their shuttle was destroyed and ARC trooper Echo was believed to have been killed.

Rex and the others then made their to a rendezvous point as they were pursued by STAPs and Anoobas. During their trek, Piell was killed by one of the anoobas and Rex and the others gave him a brief funeral. They then reached the rendezvous point, where they fought against Commander Sobeck and his droids until Koon arrived. Rex and the others were then taken back to Coruscant.

Return to Felucia
Rex then went with Skywalker, Ahsoka, Koon, Wolffe, and their men to take out a resupplied Separatist outpost. With the aid of Felucian scouts, Rex and Skywalker assaulted the outpost while Tano and Koon attacked the outpost from the sides. However, Skywalker noticed that Ahsoka had gone missing. Rex and his men then searched the outpost and the surrounding area for her to no avail.

Rex then oversaw the deployment of General Fisto's, Ahsoka's, and Commander Monnk's SCUBA troopers at Mon Cala to assist Prince Lee-Char.

Battle of Umbara
Rex, along with Skywalker, Fives and the rest of the 501st were then sent to Umbara to help Masters Tiin, Krell and Kenobi to take it's capital. After the initially landing and fighting with the Umbaran militia, Rex and the 501st were then place under the command of Krell when the Chancellor requested Skywalker to return to Coruscant. Rex and his men were then pushed hard by Krell, who pushed for full frontal assaults on the capital. During the first attack on the road to the capital, Rex was force to retreat, much Krell's disappointment.

Rex, Krell, and the 501st were then sent to capture an airbase that was resupplying the capital. Rex was then ordered to go through a gorge that would leave them exposed. Rex tried to reason with Krell to no avail. Despite the objections of Fives and the rest of the 501st, Rex convinced his men to carry out Krell's orders. As they made their way through the gorge, they were attacked by the Umbarans' crawler tanks. Fortunately, Rex and his troops were able to destroy the crawler tanks. They were then confronted by the Umbarans' MHCs, which had heavy armor impervious to their rocket launchers. Rex then sent Fives and Hardcase to infiltrate their base and use their own starfighters on the MHCs. Despite Krell's orders to push the attack, Rex and his men were able to hold them off until Fives and Hardcase destroyed the MHCS. The base was then taken and secured despite the heavy losses.

When Kenobi contacted them about the capital's long range missiles being supplied by a Separatist supply ship, Rex proposed that they should attack the ship to cut off the supplies. However, Krell proposed to attack the capital despite the missiles, much to Rex's and Kenobi's surprise. Rex was then ordered to prepare the men for the attack, despite the heavy casualties. Rex at first complied, but was then told of idea by Fives to use the Starfighter codes to infiltrate and destroy the supply ship. However, Krell objected to it. Following a mishap in a hangar, Rex then gave Fives, Jesse, and Hardcase permission to carry the mission. However, he told them that if they were caught, he would not be able to protect them. Rex then watched as they took off on their mission and stopped Dogma and Tup from informing Krell. Krell then confronted Rex, who told him that he authorized a reconnaissance mission to make his strategy more efficient. Rex the saw the supply ships explosion. Rex, Fives, and Jesse were then brought before Krell, where he reprimanded them. Despite Rex objections, Krell then had Fives and Jesse taken to the brig for insubordination.

Rex then spoke with Krell to convince him to spare Fives and Jess, telling him that the men are with him despite his reckless tactics. Despite this, Krell ordered Rex and his men to execute them, but they refused to do so. Rex and Krell were then contacted by a trooper who informed them that they were ambushed by the Umbarans disguised as clones. Rex was then sent to attack the Umbarans. Rex and his men, armed with mortars, then went into the jungle where they were attacked by the troopers. However, Rex then examined one the troopers and discovered they were clones. Rex then ran in front of both his men and the troopers, revealing the deception. Rex then spoke with the 212th Battalion platoon leader, Waxer, who revealed that it was Krell who ordered the attack. Rex then gathered his men and the remainder of Waxer's platoon together. Then, Rex told them that they would arrest Krell for treason. Rex and the men then confronted Krell, who was surprised that Rex figured it out. Krell, believing him to be committing mutiny against, refused to be arrested. Krell then pushed Rex and his men and made his escape into the jungle. Rex and his men then went into the jungle, where Krell taunted him. Fortunately, Krell was then subdued and stunned by Tupp. Rex and his men then placed Krell in the brig. During his questioning, Rex learned that Krell was trying to undermine the Republic so that Dooku or his master would make him his new apprentice and rule Umbara. When news came that Kenobi and 212th had taken the capital, Rex and the others decided to execute Krell. At first, Rex hesistated but Krell was then killed by Dogma.

Battle of Kiros & Kadavo
Ten rotations after Master Yoda last communication with Kiros' governor, Roshti, Rex, along with Skywalker, Kenobi, Ahsoka, and their men were sent to free Kiros from the Separatist occupation forces. Rex then rode with Kenobi as his gunner on his BARC speeder. Rex then finished off the last of the AATs with his rocket launcher as they approached the Separatist headquarter inside the governor's tower.

Following the capture of Commander D'Nar, Rex the went with Skywalker, Kenobi, and Ahsoka to Zygerria using the Tecora. Rex, disguised as a Zygerrian guard, went with Kenobi to find the colonists. Rex was then able to spot Governor Roshti. Rex then attempted to escape with Kenobi and Roshti, but they were then captured. Rex then went to slave auction still posing as a guard. When Skywalker was able to whip Kenobi, Rex saw his signal and attacked the guards. However, he and the others were then captured. Rex, Kenobi, and Roshti were then taken to Kadavo, to its slave processing facility..

Redemption of Quinlan Vos
In the final years of the Clone Wars, Rex joined fellow troopers, including Cody and Jesse, to a mission to prove the redemption of the Jedi Master Quinlan Vos. Once the clones began to unload equipment, it was discovered that the asteroid they were on was about to explode. Quickly, the Jedi and clones escaped the asteroid, thanks to Vos - however, the Jedi was simply fooling all of them, and was still an agent of Count Dooku.

Joining the Rebellion
Before Order 66 was issued, Captain Rex had managed to remove his inhibitor chip, thus was able to not betray the Jedi. Rex survived the Clone Wars and the Republic's transformation into the Galactic Empire. Following the Clone Wars, Rex was living with Commander Wolffe and Commander Gregor in a modified AT-TE on the desert planet of Seelos. Several years prior to the Battle of Yavin, Rex and his comrades encountered a group of rebels that included the Jedi Purge survivor Kanan Jarrus and his apprentice Ezra Bridger. The crew of the Ghost had been sent by Rex's old ally, Padawan Ahsoka Tano, to obtain information on abandoned bases that the growing Rebel network could use in their struggle against the Empire.

Rex and his comrades' first encounter with the Ghost rebels almost ended in violence when Kanan thought the Clone troopers were a threat and ignited his lightsaber. Rex's timely intervention managed to break up the fight between his comrades and Kanan. When Kanan's apprentice Ezra mentioned that he and his rebel companions had been sent by Ahsoka, Rex quickly realized that the rebels were friends and introduced himself and his companions. While meeting with the rebels inside the walker, Ezra tried to convince Rex and his companions to join the fight against the Empire. Rex laughed and declined, saying that his days as a soldier were over. After discussions with Kanan, Rex agreed to create a list of bases that the rebels could use but invited the four rebels to participate in a hunt for joopas as payment for supplying them with this information.

To allay Kanan's distrust of Clone troopers, Rex revealed that he, Gregor, and Wolffe had managed to remove their inhibitor chips. The rebels reluctantly participated in the joopa hunt with the Lasat Garazeb Orrelios acting as both the "hunter" and the "bait". Zeb was swallowed by the joopa but succeeded in killing the creature. Having completed their side of the deal, Kanan wanted his rebel companions to leave but Rex invited them to stay for dinner. While dining, the Mandalorian teenager Sabine Wren discovered that Wolffe had secretly alerted the Empire to their presence and hid the messages that Ahsoka had sent them.

Wolffe, who distrusted the Jedi, had informed the Empire in the mistaken belief that he was protecting himself and his fellow clones. Rex was shocked by this revelation and confronted Wolffe. He managed to convince Wolffe that the rebels were their friends and that the Empire was their enemy. Shortly later, the clones and rebels were visited by an Imperial probe droid which damaged their auxiliary ship, the Phantom; preventing them from rendezvousing with their fellow crew aboard the Ghost, which was waiting in space. After destroying the probe droid, Rex and his companions prepared for the arrival of the Empire.

Despite Ezra's efforts to encourage Rex and his companions to join the Rebellion, Rex was adamant that the clones would stay behind to hold back the Empire while the rebels escaped on the Phantom. A force of AT-AT walkers led by the Imperial Security Bureau agent Kallus, a perennial foe of the Ghost crew, landed on Seelos. Despite being outnumbered and outgunned, Rex and his fellow clones stood their ground. At the urging of Ezra, the rebels intervened in the fight and managed to defeat the Imperials. Without air support, Kallus and his surviving AT-AT drivers were forced to retreat into the desert. Honored that Kanan and Ezra would return to safe them, Rex and his comrades saluted the Jedi and agreed to join the Rebellion. Hera then arrived with the Ghost to pick them up. Later, Rex met with his old friend Ahsoka in space.

Wits versus Discipline
After joining the Rebellion, Rex became part of the Phoenix rebel cell, which operated a fleet in space. During one of Ezra's levitation lessons, Rex exposed Sabine and Chopper's trick which involved locking the astromech droid Chopper's feet to the floor; preventing Ezra from levitating him. When Ezra was upset about the trick, Rex told the Young Padawan about a how a Jedi General he had once fought alongside became a great warrior by combining the Force with his wits. In response, Kanan told Rex that the boy had a lot of wits but needed more discipline.

While Rex and Kanan argued about how to train Ezra, the young Padawan sneaked away with Sabine, Chopper, and Zeb on a mission to salvage supplies from an Old Republic medical base. Rex had provided the rebels with the codes to this station. Unknown to the rebels, two Inquisitors known as the Seventh Sister and the Fifth Brother were waiting for them. The rebels barely escaped with their lives. Rex was present with Kanan and Hera when the younger rebels returned with news that the Empire had more Inquisitors.

Later Rex oversaw target practice with Ezra, who was using a DC-15A blaster to try and hit a Stormtrooper helmet that Chopper was moving around. Kanan came out, sternly reminding Ezra about his Jedi training, which sparked a minor debate between Rex and Kanan until Sabine informed them that Hera had called for a mandatory group meeting.