The Final Rest

The Final Rest in contrary to many spells that trap the soul or turn the body to the status of Undeath, is an intricate ritual that can't be used at ease, often used to make sure people will not be ressurected again.
Though they are many materials that cut the connection between the soul and the body or even simpler methods used by many organizations, including Bag of Devouring, which is somewhat very common in Abaisgar, the The Free Marches and other Intelligence organizations. The Ritual is significant and allows to have the body complete, though many cultures somewhat mutilate the body.

Effect

Most Necromancy spells, speak with dead or anything that might have a connection between the body and the soul is severed.

Side/Secondary Effects

The caster is usually somewhat disoriented, having the soul of the target somewhat speaking to the recipient for a day to 10 days, while some cases report that the soul has never reached hades, often haunting the killer until it is hunted down by an undead hunter.

Source

Divine

Material Components

A personal item of the target or an item that represent the person being killed.

Gestures & Ritual

The Ritual is performed upon a weapon intended for the killing blow - however, if used after the killing blow, it must somehow reach the nervous system - while the easiest spot is more than often the eyes.

Related School

Necromancy

Effect Casting Time

Several Hours to Days

Level

A cleric capable to cast 5th circle spells or a paladin/blackguard able to cast 3rd circle spells.