|1st||Charm Demon, Quasit Familiar||+1 level of Arcane Class|
|2nd||Summoning Mastery||+1 level of Arcane Class|
|3rd||Resistances, Poison Immunity
||+1 level of Arcane Class|
|4th||Hold Demon, Telepathy||+1 level of Arcane Class|
|5th||Dominate Demon||+1 level of Arcane Class|
A demonologist is a mortal who has devoted his life to the study of demons.
Alingment: Chaotic Evil
5th Level Arcane Caster
Skill Proficiencies: Arcana, Planes
Feats: Evil Brand
Special: The character must have deliberately sacrificed a good sentient being to a Demon Lord.
Hit Dice: D6
Mana Increase: as per class arcane level increase.
Charm Demon: A 1st-level demonologist can attempt to charm a CE Fiend, as described in the charm person spell, once per day. The demon does not get to use its magic resistance on its saving throw.
Quasit Familiar: A 1st-level demonologist gains a quasit as a familiar, whether he wants it or not. If the demonologist already has a familiar, the quasit devours it and takes its place, but the character suffers no experience point loss. The quasit is treated as a normal familiar otherwise.
Summoning Mastery: When a demonologist of 2nd level or higher summons a demon with a spell he may summon up to 2 more of that same type if he wills it.
Resistances: A demonologist who reaches 3rd gains resistance to cold, fire, lightning; bludgeoning, piercing, and slashing from nonmagical weapons.
Poison Immunity: At 3rd-level the demonologist is immune to poison damage and poison condition.
Hold Demon: A 4th-level demonologist can attempt to hold a CE Fiend as described in the hold person spell, once per day. The demon does not get to use its magic resistance on its saving throw.
Telepathy: An 4th-level demonologist can communicate telepathically with any creature within 100 feet that has a language.
Dominate Demon: A 5th-level demonologist can attempt to dominate a CE fiend, as described in the dominate person spell, once per day. The demon does not get to use its magic resistance on its saving throw.