Bloodbringer

Weapon (any sword), very rare (requires attunement)

This magic blade is brimming with hungering necromancy. You gain a +1 bonus to attack and damage rolls made with it. Once per turn when you hit a creature with the weapon, you can expend up to three Hit Dice. Roll the Hit Dice: the target takes extra necrotic damage equal to the result, and you regain hit points equal to the same amount.

My blood burns in my veins. It begs for more to be spilled, and I drink: hungrily.