Fiendform

Fiendform was an alteration spell that allowed the caster to assume the appearance, and some of the abilities of a fiend from the Outer Planes.

Effects
For the duration of the spell, the caster assumed the form of a specific type of tanar'ri or yugoloth, taking on its physical attributes such as heartiness and skill in combat. They were not capable of casting any new spells, nor did they gain any arcane or fiendish powers, such as the ability to gate in creatures from other planes of existence.

Anything that occurred to the spellcaster while in the fiendform still affected them once its duration was over. If they were killed before the spell ended, they had the chance of dying once they reverted to their normal form. While it was possible for the spellcaster to simply fall into a coma for a matter of hours, it was more likely their death would send them to the Abyss, reformed as a mane. If this was the case, their body could not be resurrected upon the Prime Material plane.

The fiendish form the caster transformed into was entirely random, but limited to that of an alu-fiend, arcanaloth, balor bar-lgura, cambion, chasme, dergholoth, mezzoloth, nabassu, nycaloth, succubus, vrock or yugoloth.

Casting
The spell could only be cast by evil-aligned arcane spellcasters. It required verbal, somatic and material components, the latter of which was a crystal statue of any type of fiend, worth at least 3000 gp. While the statue was destroyed upon the end of fiendform's duration, its premature destruction resulted in a similarly early end of the spell's effects.