Ring of death stopping (5e Equipment)

Ring, Legendary (Major) (requires attunement)

this ring was made to stop death.

Death stopper If an effect would kill you instantly (such as failing a save induced by a talisman of pure good) it instead leaves you a 0hp. It also stops you from being forced to fail death saves and you can't be killed by overwhelming damage or effects that kill you when you are reduced to 0 health.