Possession and Summoning

[leegi0n]

Playgrounders,

I have a couple questions:

I would like to create an NPC/baddie of appx. CR16 that is essentially a teen wizard apprentice who has been possessed by a fiend. That fiend is using him as a vehicle to summon other fiends and help create a massive gate to the material plane.

What would a build like that entail? Would it involve a multiclass? How would possession come into play and how would it affect the CR if at all?

Thanks in advance ~

[Feralventas]

Wizard3/Master Specialist Conjurer4/Fiend Binder9.

Core, Complete Mage, Tome of Magic.

Make sure that the demon you're using as your Actual BBEG has levels in Fiend of Posession, though I suppose any demon can possess someone via the Book of Vile Darkness rules.

Character is going to have to be a hell of a savant; being a wizard is akin to having a PHD; you would normally spend decades starting, learning, getting credited, and gaining the admission and recognition of the magical community both among peers and institutions. Accomplishing this at a young age would likely justify his hubris in summoning and trying to bind a demon.

So Wizard as an initial bachelor's degree, Master Specialist for master's degree, thesis and PHD in Truenaming. All before age 20.

You'll need to spend at least two feats to make this work well; one is Craft Wondrous Item to be able to build the gear and items needed to make Truenaming really sing for you, and the other being a feat to treat Truenaming as a class skill from day 1; this will be your 1st level feat. Perhaps the wizard first started out by reading the True Name of their Imp familiar and gaining their insight from below, gradually being manipulated into their current predicament.

[TuggyNE]

Wizard3/Master Specialist Conjurer4/Fiend Binder9.

I don't know about you, but when I hear "apprentice" I don't generally think of a level 16 character. Seems like most of the CR 16 desired should be provided by the possessing fiend, not the apprentice.

[leegi0n]

right right....the CR should come from the fiend and how it channels through the teen. What then?

The teen apprentice is actually only about level 4-6 by himself. How about that? How should that look on paper?