R2-C4, frequently referred to as "C4," served the New Republic during 34 ABY as an R2 series astromech droid. R2-C4 was a part of Kazuda Xiono's squadron on their mission to deliver intel on the First Order to the Resistance. First Order pilot Major Baron Elrik Vonreg attacked the squadron, threatening to end the mission in failure. After Mia Gabon and Hugh Sion, members of Xiono's squadron, made their escape to hyperspace Vonreg landed a hit on Xiono's and R2-C4's X-wing. Resistance Commander Poe Dameron arrived in time to save Xiono and R2-C4. Working together, the New Republic members and Resistance commander were able to chase the First Order pilot away and complete the mission. When Xiono joined the Resistance for a mission on Castilon, R2-C4 remained with the Resistance.
R2-C4, also known as "C4," was a New Republic astromech droid that operated approximately thirty years after the Battle of Endor. R2-C4 accompanied a New Republic squadron, led by pilot Kazuda Xiono, on their mission to deliver intel to Resistance Commander Poe Dameron. R2-C4 rode in the astromech socket of Xiono's T-85 X-wing starfighter. Xiono's squadron was attacked by First Order TIE Fighter Pilot Major Baron Elrik Vonreg. Xiono informed R2-C4 that he did not know where Dameron was but was certain he would arrive soon. Due to the danger, Xiono gave the command for the rest of the squadron, pilots Mia Gabon and Hugh Sion, to retreat back to base while he delivered the intel.
After Gabon and Sion fled the scene, Vonreg landed a shot on Xiono's X-wing. Xiono requested confirmation that his squadmates successfully jumped to hyperspace and cheered at R2-C4's response, but soon discovered his X-wing's power was down. Dameron arrived to save the New Republic pilot and droid by blasting incoming warheads and drawing Vonreg's attention. Xiono instructed R2-C4 to give him control of the weapons. Xiono requested Dameron lead the First Order pilot towards him. Dameron lead Vonreg towards Xiono and pulled away to let Xiono open fire and damage Vonreg's TIE. Vonreg was forced to retreat before Dameron could finish him off.
Poe Dameron and Kazuda Xiono talk while BB-8 and R2-C4 observe
With the fight over, Dameron instructed Xiono to come abroad and the Resistance would fix his ship. A CR90 corvette appeared out of hyperspace that Xiono and R2-C4 boarded. Onboard they met with BB unit BB-8 and Dameron. When Dameron left to speak with General Leia Organa a flustered Xiono requested Dameron tell Organa he said hello. The droids commented amongst themselves to which Xiono requested them to stop the commentary and show him where the refresher was. While Xiono refreshed himself BB-8 left to speak to Dameron, which Xiono discovered after he emerged from the refresher. Xiono asked R2-C4 which way BB-8 went and then insisted he would have a look around. He instructed R2-C4 to remain behind—an order the droid ignored.
Xiono agreed to join the Resistance and Dameron assigned him a mission on Castilon. R2-C4 was left with the Resistance, becoming a member of the organization.
R2-C4 was manufactured by Industrial Automaton. The droid had a blue chassis with gray, white, and yellow plating. A light blue sensor was located on the droid's dome.
R2-C4 was first pictured in a trailer to introduce Team Fireball, featured alongside concept art of Kazuda Xiono. R2-C4 appeared in the first part of the two-part episode "The Recruit," the premiere of the television series Star Wars Resistance, which premiered on October 7, 2018. R2-C4 was only referred to as "C4" in the episode but received full designation as R2-C4 in the 2019 reference book Ultimate Star Wars, New Edition.
- Ultimate Star Wars, New Edition