The answer is Shadowheart. If you want an evil trio with no problems, she is the final link. Yes she has secret light within her, but on the surface she is quite dark and callous. It is against her true nature, but you can probably corrupt her in this way by encouraging her clinging to Shar worship.
Both Wyll and Gale can leave if you go the tadpole/Absolute/goblin route. So it's not worth it. You won't be able to befriend SH in Act 1 though if you go that route, but she still remains. If you're playing as evil as you can be, you probably aren't even interested in romance so it doesn't even matter lol.
You are most likely right.
But I would prefer not having her in that play-through
But seems she must be a part of every playthrough.
Hope we will get a few more origin characters in the full game.
