Ra Moon

Ra Moon (ラ・ムーン) is an ancient alien super computer, found by Dr. Wily three weeks before the beginning of Super Adventure Rockman, who revived Wily's Robot Masters from Mega Man 2 and Mega Man 3. Ra Moon seems to possess advanced technology that can create robots in a blink of an eye.

Story
Ra Moon crashed on Earth 20,000 years prior the events of the game. According to him, he gave humans the capacity to harbor violence towards each other, the technology and tools to further their hatred, and made them construct a temple for him. His plan was to have the humans wipe each other out and then rule the Earth with an army of his own machines. However, Ra Moon grew tired of the humans' violence and decided to delay his plans, burrowing himself underground alongside the temple.

Years later, Dr. Wily found Ra Moon in the Lanfront Ruins when investigating its electromagnetic field. Ra Moon analyzed Wily's computer and used its data to recreate his robots from DWN-009 Metal Man to DWN-024 Shadow Man, and assisted him on creating Ra Thor. Mega Man fought against the 16 revived robots and defeated all of them, but was knocked down in the last battle against Spark Man, being captured by Wily. Wily and Ra Moon revived all the robots again with the exception of Shadow Man, which could not be repaired. When Wily activates Ra Thor and orders him to destroy Mega Man, Ra Thor attacks Dr. Wily's robots, and Ra Moon reveals that he was only using Wily and plans to destroy Earth. Wily's robots free Mega Man and he fights against Ra Thor to save Wily, destroying him. After the battle, Ra Moon says that Ra Thor was just another of Wily's imperfect machines, and shows that he had secretly created the New Yellow Devil, his appearance being based on the data Ra Moon got from Dr. Wily's Yellow Devil. After a difficult battle, Mega Man manages to destroy both the New Yellow Devil and Ra Moon by firing a charge shot with the Mega Buster in both arms, also taking down the temple.

Other Media
Ra Moon appears in Archie Comics' Mega Man comic series during the Spiritus Ex Machina arc. His role is similar to his role in the game, except that the only Robot Masters he rebuilds are from Mega Man 2 and he serves as the initial creator of the Mega Man 3 Robot Masters save Shadow Man (which was already in existence). It later appears briefly in the standalone story arc "Rock of Ages", where it had evidentially turned against Dr. Wily and Wily is begging Mega Man to destroy it. Interestingly, Mega Man reacts as if he had fought and destroyed Ra Moon before. It will turn against Dr. Wily in Mega Man 28.