In 99.4% of the Lore i know Succubus are from a Hell/ Abysmal Plane.
as for the Spells, Well it is typically the Type of your teacher, until that teacher Releases You from his or her control. After that time you get spells in a Add hock (random Manner, is the Spell useful? can you use that spell in your everyday life?)
in the School Setting you have. the MC can pull (from my view) most teacher there at the School ( from Darkness Magic to Light, Demon, Angel, Any of the Fae races, )
I like your game(Fantasy School)
I was replying to S1nsational's Comment from 19 days ago.