Cool Anime Its old but I like it.
About A Teenage boy Name Setsuna Mudo who's the reincarnation of a very powerful angel named Alexial who turned against God and all other corrupted angels.
Its more of a Romance story really seeing as Setsuna is in love with..yes with his sister. Who's also the reincarnation of angel. The demons and other angels who's not corrupted try to resurrect Alexial.
Sadly it only had three episodes...Mainly to only introduce you the manga. Bastards...
Anyway If you have any interest heres were you can see.