Sacrifice

This is one of the four Warlock's pet Voidwalker's spells.

Sacrifice consumes a portion of the Voidwalker's health and gives the Warlock an absorption shield that is similar to a priest's Power Word: Shield abiliy. The ability consumes 25% of the voidwalker's base health, so as long as the voidwalker isn't near death, there is very little chance that the use of this ability will kill the demon.

The duration of the Sacrifice shield is 30 seconds.

Improvements

 * Demonic Brutality - Increases damage absorbed by 10/20/30%.

Tactics
It's very useful when using Hellfire, making a getaway or to extend your life in PvP combat. Using Sacrifice in the Battlegrounds is especially useful because when you die and resurrect, you get your Voidwalker back without having to re-summon it. Even if you are not Demonology specced, this ensures that'll you be able to sacrifice him at least once without having to re-summon.

Having Fel Synergy will allow you to heal the voidwalker back for the health he loses very quickly and makes the use of the shield a non-issue as long as the pet is in reasonably good health.

Other than shields which restrict your actions (e.g. the Paladin's Divine Shield and Divine Intervention), this is the strongest absorption-type shield in the game. It is possible to summon another demon while under this shield, unless you're faced by an enemy that can quickly overwhelm the shield with sheer damage. The Fel Domination and Master Summoner talents can make this a much more likely tactic -- if you have Soul Link, you probably have these, and in an emergency you can Sacrifice your Voidwalker, resummon it (it will now be at full health), and Soul Link with it again.

Patch Notes
As of patch 3.1.2 the spell no longer kills the Voidwalker, but instead only sacrifices a portion of its health.

Trivia
This spell was formerly known as "Sacrificial" Shield during the Beta tests.