Delay Death

You give one willing creature you can see the ability to keep fighting despite near-lethal wounds. When the creature drops to 0 hit points without being instantly killed, it does not become unconscious but can keep acting normally. The creature still makes death saving throws and dies if it fails three times or if it takes enough damage to cause instant death. The creature does not automatically fail death saving throws when it takes damage. Delay death has no effect on a creature already at 0 hit points when the spell is cast.

Classes: Cleric, Warlock, Wizard

Subclasses: Arcane Trickster Rogue, Divine Soul Sorcerer, Eldritch Knight Fighter

Subclasses (legacy): Favored Soul v2 (UA) Sorcerer, Favored Soul v3 (UA) Sorcerer

Source: BoLS (3pp), page 42