Publication:Dread Codex/New Spells/Voice of the Grave

You attempt to trap an incorporeal undead within your own body. If you know the undead creature’s birth name, the spell has unlimited range and the undead suffers a -2 penalty on its saving throws. Otherwise, you must be able to see the creature, and the spell is countered if the undead is protected by protection from good or a similar effect.

Once inside you, the undead gains control of the body. The undead keeps its Intelligence, Wisdom, and Charisma, Hit Dice, class, base attack bonus, base save bonuses, alignment, spells, skills, feats, and spell resistance. The body retains its type, subtypes, Strength, Dexterity, Constitution, hit points, natural abilities, extraordinary abilities, supernatural abilities, and automatic abilities. The undead cannot leave your body voluntarily, but can otherwise act freely in its new body. When the spell’s duration ends, the undead reappears wherever it was when the spell was cast. If you die while the spell is active, both you and the undead are slain.

Voice of the grave can be combined with magic circle against evil and similar spells as if it were a calling spell. Doing so extends voice of the grave’s duration so long as the undead does not break free of the circle.

A number of times per day equal to your Charisma modifier (minimum of 1), you can try to take control of the undead in your body. The undead must make another Will save or act as you desire for 1 round. As this is the only action you can take while possessed, treat it as a perpetually readied action that can respond to anything the undead attempts.