My party just somewhat survived the assasin's attack at the beginning of Soul Pillars
I'm running the following group:
Blazmeth, Half-Black Dragon human (suel), Fighter/Hex-Blade, LVL 12.
Saber El-Rashid, Human (Baklunish), Cleric/Diviner/Mystic Theurge of Celestian LVL 10
Vor, Human (Suel), Barbarian/Cleric/Templar of Kord LVL 11
Iryth, Human (Suel/Oeridian), Cleric/Master of Shroud of Nerull (yes he hides it) LVL 11