Of course this is an effective spell to use in one-on-one combat, and great if you have regeneration, but Orcus is not alone, he has followers out the wazoo (gods tend to). If you can kill everyone around him, then hope that no one shows up for 50 turns, this could work. IF someone shows up, you're in trouble, since the sustain standard leaves you very vulnerable.
That doesn't matter. Even if the example encounter includes other monsters Orcus is a solo monster and like all other solo monster they are supposed to be a adequate challenge without other monster support.
Except that they aren't because of the killer combos.
Have to roll an 8 to hit...Not so good. Now I'm sure there are various things that would help you out at such high levels, but a maximized hit is going to deal about 29+3+6+18+6d12=95 on average. I think I assumed every advantage this guy could possibly have. I'll also assume that his weapon is vorpal, so he can use the vorpal daily on one of those hits and the reroll ability on the crit-dice. I think this ends up with you having to hit him 15 times at least(before the vorpal stuff its 17). Thats going to be tough.
