Fiendish Transformation
System: Pathfinder | SRD
Level: 6
School: transmutation
Casting time: 60 minutes
Components: V, S, M (powdered obsidian, vial of unholy water), F (the severed head of a good-aligned outsider whose CR was 10 or higher)
Skill checks: Bluff, Diplomacy, or Intimidate (choose one) DC 31, 3 successes; Knowledge (arcana) DC 31, 2 successes; Knowledge (planes) DC 31, 1 success
Range: primary caster
Duration: 1 week
Saving throw: none
Spell resistance: no
Backlash: The caster takes a –4 penalty on Will saves for the next 24 hours.
Failure: The caster gains 1 permanent negative level and must succeed at a Will saving throw (DC = 16 + caster’s Charisma bonus) or be transported to a random location in Abaddon, the Abyss, or Hell (based on the ritual), as per plane shift .
A solitary ritual, the rite of fiendish transformation must take place in an area bereft of light, save for that of a single candle. The candle is centered on a circular sigil crafted out of powdered obsidian and lined with unholy water. As the ritual commences, the caster holds aloft the severed head of a good outsider, through which a fiendish patron speaks. The circle channels the patron into the head without summoning its full presence, and the primary caster can choose which evil plane the creature comes from (Abaddon, the Abyss, or Hell).
A grueling negotiation determines whether the ritual succeeds or fails. Success imparts the half-fiend template to the primary caster for 1 week, while simultaneously damning the soul of the primary caster to the plane he has contacted.
Source: Occult Realms pg. 56