Reviler

Normally invisible, a reviler shows itself only while trying to possess a victim: a swooping phantom with a leering skull face and grasping claws. Soft, eerie whispers sometimes betray it. Spells that detect undead, evil or invisibility expose it, and true seeing reveals its real shape. Revilers whisper to one another and keep every language they spoke in life, usually Common among them.

It can claw twice, but only while visible. Alternatively it gives up both claws to make a single touch attack; a good victim touched must make a Wisdom check or adopt the reviler's alignment until someone casts remove curse or dispel evil. It gets one attempt per target, and anyone who resists is immune to that reviler for good.

Its powers work at 10th level: animate object, spectral force, stone shape and suggestion once per day each, and detect good, detect magic, telekinesis and wizard lock thrice daily. Twice a day it can turn up to a cubic foot of liquid within 10 feet into Type I poison lasting 2d6 hours, though not fluids inside living bodies. Packs of revilers foul wells, springs and ponds this way; purify food and drink, cure disease or neutralize poison undoes it.

Being incorporeal, it can drift through solid matter at half speed. Mind-affecting magic, poison and paralysis do not work on it, and it needs +1 or better weapons to hit. Holy water burns for 1d8 a vial; priests turn it as a spectre; holy ward or dispel evil banishes it permanently.

Evil gods make revilers, haunt-like spirits, to spread dread, grief and discord. They hate goodness and purity, trying to corrupt them or steer them toward evil, and the people they corrupt become instruments of chaos. They lurk in abandoned buildings, ruins, catacombs and cemeteries, usually bound by their master to one site, anything from a house to a whole desolate domain. Their lairs reek of evil, drawing other foul monsters, especially undead.

Each reviler began as the soul of a slain, wicked person. It serves its dark lord hoping for release, but undeath only feeds the spite it had in life.