If they are kinda tapped out, he'll have to fight maybe by RAW. If they barrel through the other parts of the villa okay, I'll have him use like a varient of the spell so he can get sneak attacks off. I mean for Horus's sake I have a blaster Sorcerer. I have 1 guy who's kinda used to building strong but as a group they are maybe swinging below or at average. It's more balance wise on my end than the players. so even WITH the extra's I tossed in, he went down FAST.

On the other-hand, if your party has been struggling, Guant will need to pick: Sneak Attack + Poison, or Spectral Hand + Soul Drain or, Cast on the Defensive, and stack almost EVERYTHING, while flanking. let Spectral Hand flank for the fight, and drop those Sneak Attack Spells with Soul Harvest. If, for example, you've been stacking extra HD and/or templates so far. IE: How much adjusting are you needing to make, balance wise? 'How much difficulty has my party had thus far, vs what's as written?' I think, that personally, I'd ask yourself this basic question: