Not "Evil" for the sake of it, but "complex". Driven.
This. You can stop all discussion from here on out, this is all you need.
Not just complex, evil should be rewarding. Why people steal or work for mafia? They do if for profit. If the whole benefit is having sex with some drow who sounds like an old truck and wants to kill you afterwards then it is not exactly rewarding. It seems like a bad investment.
Well they also do it out of fear, or depseration, but the rest of the point works.
One of the thoughts I had was regarding Sezza the Goblin (the one in the Tiefling cell within the Grove). She herself tries to sell us on the Absolute and we can free her and sneak out or presumably fight our way out (last time I went through front door a fight ensued) but Sezza dies immediately). Why can't I talk my way out, be deceiptful and say I am using the Goblin to get closer to the Goblin leadership in order to murder them. I mean it's technically a solid plan as far as the Tieflings should be concerned. If I fail to convince them, maybe I could pretend to put Sezza back in her cell (escaping via the back route) / sneakily murder the guards and get out said other way when they insist on locking her back up.
Either way, I am not interested in the Absolute, why would I be? Later, oh later maybe, but Sezza could be just such a hook to ensure her mistress could help me (That or Sezza needs to sell the abilities of the Absolute more so I think to myself that they "could" be an option). With Sezza in tow through the Goblin camp I can "skip" the insults and be sold the concept of helping Minthara and destroying the Druids. Power could be mine!