Raise the Dead

Level 6.

This ritual allows the Thaumaturgist to do just that - resurrect a dead being, allowing it once again to dwell in the world of the living. This is not a "resurrection" in the truest sense, however; the creature is not alive, nor is it undead, but is in fact as dead as the day it died. The corpse is animated by a spirit the caster forces into it during an eight hour ordeal. This ritual involves the pouring of black candle wax over the throat and heart of the corpse. The wax is what initially binds the spirit into the body. The corpse must also be branded on the forehead with a mystical symbol meaning "debtor."
The entire ritual must take place within a circle of salt, the diameter of which must equal the length of the corpse from head to toe. Furthermore, the ritual requires complete darkness, save for the candle's light. The body used must be fresh enough to have tissue still remaining on the bones, for the bondage of the spirit lasts only while tissue remains (decomposition continues at the normal rate); the fresher the cadaver, the better. This is a tortuous existence for the spirit trapped within the rotting frame, and most resurrected beings wish release as soon as possible. This is the Warlock's main bargaining measure to get the spirit to do her bidding, for only she holds the power to release the spirit. Other than that, the immured being may do as it wills with its new body. Obviously, the spirit used must have been summoned or obtained beforehand. Statistically, the creature has Physical Traits equal to half those the body possessed in life. While the spirit is trapped within the corpse, its Traits are halved as well.
A destroyed vampire cannot be raised by this ritual.

Errata: Like a lot of rituals, this one does not specify what kind of spirit it is using. It seems most likely that it uses a "living" spirit, because there are no thaumaturgic rituals written that bastardize Necromancy in such a way as to allow a Thaumaturge to summon wraiths.