When cast on living party or raid members, the soul of the target is stored and they will be able to resurrect upon death.
If cast on a dead target, they are instantly resurrected. Targets resurrect with 60% health and 20% mana.
The shadows will grant you another life; try not to waste it this time. — Pidge Filthfinder (TCG)
Soulstone is a core warlock ability learned at level 18. It creates a [Soulstone] that stores the targeted player's soul (or the warlock), allowing that player to resurrect. If the spell is cast on a dead player, that player is instantly resurrected.