User blog comment:DeathGodPrayer/Talk About What You Want!/@comment-50.11.177.49-20121224172318/@comment-1359322-20121225185809

Hmm the author never did reveal what happen during the war between the Anti Satan and Old Satan faction he only revealed the result of the war were the old Satan faction retreated to the back part of the Underworld. Well the author did let some info out, such as Sirzechs and Ajuka being the ace of the Anti Satan faction for obvious reasons. Sirzechs meeting Grayfia and the two of them fell in love (their love story were even made into a movie). The current four Satans are members of the Anti Satan faction. And the newest info he gave were the House of Lucifuge. Well i guess the Extra Demons isolated themselves because they did not want to involve themselve with the current Devil government.

BTW the author did mention that he is interested in doing a Volume 0 about Sirzechs' past, so who knows we might actually know the details.