Yeah, but that's in order to get Lethicite. If the devil arrives at your doorstep, and offers you a deal for your soul, could you just be like "Okay, but instead of me, I'll give you my sister's soul".?
I'm not going to fault you for not reading around the forums here for info but.....
-Level 3. Selling your soul to one of the Seven. Kitsune TF for Keros, Valkyrie TF for Lumia, etc, etc.
Thats for getting some special TF's, and I assume the selling your soul part can be used in other things as well, say..... a perk? Demons are no longer the only "Soul takers". There are now actual gods (Marae wasnt what Id call an ACTUAL one) that you can sell your souls too. Demons are just the other side now.
However, Demons didnt really have you "sell" your souls to them. They TOOK it from you, and whoever they wanted it from. Hell, YOU took it from people. No selling there.
There would be consequences btw, for not using YOUR soul in that Devil analogy. Your think in IRL terms. But in CoC2 terms, the character that loses the soul is gonna have a debilitation of some kind.
If you sell say Cait's soul (Cat girl companion) to Mallach, the God of passion and lust, she may become some hyper sexed slut (bimbo maybe?) who can no longer heal and she is THE Healbot of the game, BUT she can do MASSIVE lust damage now and has some KILLER sex scenes to boot. Lethicite isnt involved.
On the other hand, if you or a demon corrupts Cait enough to have her LOSE her soul, she becomes a demon. And Im not sure if whatll happen then.
The demon part is probably something thatll only happen for NPC's. And Companions as I said, is Iffy all on its own.