Isao Kofun (Conflicted Hearts)

Isao Kofun is an Legendary ZAFT Ace pilot and the first ever Regulator-type Perfect Newtype that became the protege of Rau Le Creuset during the First Bloody Valentine War, Isao was once friends with Takeo Yamato and since losing all his family and friends - without even learning of their connection - he developed into an obsessive desire to be with him and eventually desired to rule the world together, Isao is so twisted that he claims that he would gladly massacre millions and become the Devil so long as Takeo became his Archangel.

He is commonly known as the Red Devil by enemy pilots and the ZAFT Reaper.

Trivia

 * Isao is a male Japanese name meaning "Merit".
 * Kofun is a period of Japanese history that takes placed before the Yamato period, which in turn, the Yamato period is then replaced by the Asuka period.
 * Ironically, given his insane duel nature, Isao's birth constellation is that of the Gemini.