Soul-powered NPC

[j_spencer93]

I am trying to make an NPC who has disrupted the natural order and is using souls of those he kills to strengthen himself, is there an classes, items, etc that would allow this/make this more interesting? Even thought about maybe making him a minion of the 8th lord of hell and he is collecting soul to allow his lord to challenge Asmodeus.

2nd question, would there be a feasible way to temporary imprison Asmodeus?

[Alex12]

I am trying to make an NPC who has disrupted the natural order and is using souls of those he kills to strengthen himself, is there an classes, items, etc that would allow this/make this more interesting? Even thought about maybe making him a minion of the 8th lord of hell and he is collecting soul to allow his lord to challenge Asmodeus.
Book of Vile Darkness has some very evil things you can do with souls. My personal favorite thing is to use them in crafting, where a trapped soul pays for 10 XP worth of crafting, but makes the item evil. Combine that with the rules for pain extraction and the rules for sacrifices, and you can pretty easily subsidize 40+ crafting XP per level 1 commoner. Torture them for their Con score days (we'll assume 10) while they're hooked up to a pain extractor to get 10 doses of liquid agony, each worth 3 crafting XP, sacrifice them to Asmodeus for some number of dark craft XP (the number is based on a K(religion) check, minimum DC is 15, trap their soul with a dark altar stone or thinuan dagger, and spend that for 10 more crafting XP.
Thinuan, a special material from I believe Complete Warrior, is a substance that absorbs the soul of anyone touching it when they die (including the wielder). It can hold one soul at a time, so if someone else dies while touching it, it displaces the first.

BoVD also has the Soul Eater PrC, which seems like it would work alarmingly well with a tibbit (a race from Dragon Compendium, basically a species of were-housecats)

2nd question, would there be a feasible way to temporary imprison Asmodeus?
At the level Asmodeus is at, you're pretty strictly in DM fiat territory when it comes to imprisonment.

[Werephilosopher]

Soul Eaters (http://dndtools.eu/classes/soul-eater/) gain power from draining energy from their victims... but it's not a lot of power, and it wears off after 24 hours, so they'd need a continuous supply of victims. Works thematically, though.

[Kuulvheysoon]

Soul Eaters (http://dndtools.eu/classes/soul-eater/) gain power from draining energy from their victims... but it's not a lot of power, and it wears off after 24 hours, so they'd need a continuous supply of victims. Works thematically, though.

In that same vein, there's the Necrocarnate from Magic of Incarnum. It's abilities wear off after 24 hours, as well.