C is a fictional character from the Gundam Build Fighters anime series.
According to Mr. Ral's information given to Reiji and Sei, as well as Baker's information given to Chairman Mashita, C is a member of the Gunpla Mafia, a group that uses Gunpla Battle for illegal monetary gain. Up to the time of his arrest by Takeshi Iori he had committed thirty-six crimes.
C has the ability to spy on his targets as well as gather data on their abilities. He was also able to infiltrate the servers of the World Tournament and hack his way into the ninth race by sneaking into a low security datacenter below the stadium. He was also able to fistfight Mr. Ral on nearly equal footing.
C is a mysterious Gunpla Fighter hired by Baker to eliminate Sei Iori and Reiji during the seventh period of the world tournament. He tried to sink their Star Build Strike Gundam with his Hell Zeong Marine by crushing it underwater. However, his plan is foiled by Mr. Ral.
He later insisted on redeeming his prior failure by defeating Reiji. In order to do so he inserted his Hell Zeong Galaxy into the battle system at the Hobby Shop via his briefcase. He was defeated once again thanks to Reiji and Aila's partnership, with Aila using a Command Gundam and Reiji using a Beginning Gundam, which had been built by them with the assistance of Takeshi Iori.
After this defeat, he was arrested by Takeshi Iori, who revealed himself to be an International Gunpla Battle Referee, for thirty-six crimes.