Dr. Armond, also known as Dr. Meta-Evil or Dr. Hebereke in Japan, is the true leader of the Rubberobo Gang.
In the anime
In the anime, Dr. Meta-Evil is trying to get his hands on Rare Medals which he can use to take over the world. He first appears on a TV screen in the headquarters of the Rubberobo Gang. During his first appearances, his face isnt visible but his cat is. Once one of the 4 Rubberobo leaders got his/her hands on a Medal, they summoned Dr. Meta-Evil, who then appears as a spiraling cloud in the sky. After a while he realizes that the Rubberobo Gang isnt functioning well enough, so he sends down Mega-Emperor to get his hands on Metabee's Medal. He succeeds getting Metabee, and uses Metabee's Rare Medal to control all the Kabuto Medal-powered Medabots in the world.
When Ikki and his friends break into his base, he reveals himself and also that he is part human and part Medabot; a cyborg. After he is defeated in Robattle, his cat, who reveals himself to be sentient, removes his Medal and places it inside Mega-Emperor. After Mega-Emperor is defeated, Meta-Evil appears again when Ikki and Victor fight in the World Robattle Championship. He reveals that the stadium is in fact a giant resonator that he wants to use to turn all Medabots against humanity. His plan almost succeeds if it wasn't for the friendship between Ikki and Metabee. With his second plan thwarted, he summons a giant Babbyblu. His giant Medabot is defeated by a giant Metabee, piloted by the real Metabee. After his defeat, Dr. Hushi descends from outer space and tells Meta-Evil that the Medabots dont want to rule humanity. He offers to take Meta-Evil with him, and Meta-Evil then leaves for outer space.