the seven brothers are asmodeus, belphegor, beelzebub, satan, lucifer, leviathan, and mammon.

belphegor, satan, and mammon hate lucifer. 
mammon is greedy, and super clingy and calls you ’his human’.  belphegor goes by belphie, is a yandere, and is always sleepy. leviathan is a otaku gamer, and he loves anime. lucifer never gets sleep, and is serious. asmodeus is super flirty, and loves charming you. satan loves books, and cats.

they call lucifer “mom“ as a joke.