In regards to Wyll's patron (the lovely lady to has wrapped herself about him) is she a succubus or an Erinyes? And if she is a succubus is he a devil or a demon, because apparently Succubus can be both. Though given the prominence the Nine Hells are playing, I am going to go for a Devilish Succubus. Raphael sure has some competition.
That is also a very interesting staff that Shadowheart is wielding.
I am not an expert for 5E, but in older games succubi were demons and erinyes were devils.
The fact that the game plays ( partly ) in hell ( home of devils ) has no influence on the question if he made a pact with a demon or devil before.
First, the game may also lead us to abbys at some point.
Second, both demons and devils can have reasons to send a minion to hell to do something for them.
Third, the characters go to hell because they get kidnapped by Illithids. It is unclear if they want to go there or if they were send there for other reasons too.
Looks like we have 2 moderators now. Vometia is no longer alone.