Execute

You magically prevent a creature from escaping death, and that creature must make a Wisdom saving throw or be cursed for the duration of the spell. While cursed this way, the creature is killed when it is reduced to 0 hit points and cannot regain any more than 10 hit points in one round.

This spell ignores the effects of death ward, traits such as Undead Fortitude, Relentless Rage, and any similar effects or spells. This spell even foils the Mythic trait of some creatures and doesn't allow a lich to use it's Rejuvenation feature if it has died while the spell was active. This spell has no effect on deities.