Not sure about Astarion, since even tho he is a Vampire spawn and they are evil "by nature" ... most other Vampire spawn rules dont apply to him either. O_o
But laezel isnt evil by nature at all ... that more like cultural evilness.
---
Anyway personaly i find it much harder to create Evil Party than Good ... for one we only have two evil companions, and for two every sensible person would kill astarion right there when he attack us ... so that leaves us with party of 2. :-/
It's not the "spawn" part that makes him evil, it is the vampire part, or actually the whole, being undead part...
But i also find it hard creating a party as an evil character too. Since as you say, one companion is a instakill bcs of him attacking me, and i am not really sold on the other two as well...
