Well... This story was inspired by my favorite anti-hero/villian protagonist named Joukyuu Kunitoshi, the main character of the manga series, Aiki and Aiki-S, and Donquixote Doflamingo, one of the popular villain character from One Piece series. I originally planned to make Geist into a righteous, kind, young man who was admired by everyone around him due to his parent's death but this was seen as too cliche already used by most fan fictions I've seen. After this idea was discarded, it hit me this point! What if......there was a villain protagonist that can has both power and twisted personality same as Rizevim Livan Lucifer, but standing with the canon characters in a comical, tormenting way. I mean, Rizevim wants to cause chaos and break hell on everything he finds, while I wanted Geist himself dreamed of world domination and conquests, which it could become a hindrance to his plan.
As for the worlds, characters, and etc. that Geist involves were inspired from many light novels, mangas, and animes such as:
Highschool DxD (Obviously... and world inspired from another light novel of Highschool DxD's, Slash Dog where there is a Country of Oz, separated and existed inside the Dimensional Gap. And there's the world of ExE, mentioned in the light novel where there are mainly two sides ruled by their respective gods).
Drifters (This manga and now anime, was inspired for the world war taking in place in the world of Drifters, and this is inspired for Oc's story and location's sake, which it is Geist's path to conquering the world as the characters in Drifters did).
Kyoukai Senjou no Horizon (Horizon in the Middle of Nowhere) (This is a inspiration of the world and the characters I'll be putting in for Geist's story elements.)
and...more will come for inspirational sakes!~