Magnanimous is first seen in the episode, "Battle Royale", monitoring Coop fighting a random robot, exclaiming that he "might be able to use this human fool." He then appears in front of Coop, Jamie, and Kiva Andru, and offers Coop an opportunity to fight for him in his tournament. Coop immediately accepts and enters the Galactic Championship Federation Bash Fest. After seeing Coop's first two fights, he confronts Coop and claims that he was right and that Coop will make him rich. He then tells Coop that he's going to lose the next match. Coop defies him and begins winning the third match. Magnanimous then decides to cheat and binds Megas with metal tentacles that appear from the stadium. However, Kiva overrides the system and releases Coop, allowing him to easily win the third match. Magnanimous becomes angry and goes to see who is hacking his stadium's system. He discovers Jamie and Kiva, then takes them prisoner, putting them in a forcefield cage dangling over a quantum singularity. He then threatens Coop, saying that he will drop them into the quantum singularity if Coop doesn't start losing. Kiva and Jamie manage to escape from the cage and get into Megas. Subsequently, Magninmous releases all the other fighters in an effort to take down Coop. Coop easily defeats all the fighters, but is then attacked by Magnanimous himself inside his Sonic Abominator mech. Coop easily defeats him using the Jammer and then cuts Magnanimous from his mech, sending him into the quantum singularity. His base then blows up and it's assumed that he was gone for good.
He reappears in "The Return". When Kiva asks him how he got out of the quantum singularity, he merely states that "it wasn't easy". He starts by claiming that he's trying to rebuild the GCCF, and revokes Coop's title as champion and demands the championship belt back. Coop refuses, and inexplicably says that it's in his garage. Magnanimous decides to have his current five fighters race to Coop's garage to grab the belt. Coop manages to beat all five fighters and declares that no one can beat him, and he'll take on anyone who wants to challenge him. Magnanimous takes advantage of his statement and offers a 500,000,000 credit prize to whoever can beat Coop, hundreds of robots and aliens then appear to fight, T-Bot among them. Coop continues fighting until Megas shuts down. Magnanimous then takes out the last of the fighters in his newest mech. He then revealed that the real reason he returned was for revenge. After a grueling fight, Coop manages to rip Magnanimous out of his mech. Coop, while holding Magnanimous in Megas's hand, reveals to the other fighters that there is no prize for beating him. He is then thrown to the ground, where he tries to reason with the other robots. He then creates and jumps into a wormhole, followed by the angry robot challengers.