Bloody Dagger

Weapon (dagger), rare (requires attunement by a fighter or a rogue of non-good alignment)

This +1 dagger is permanently covered in congealed blood.

Radiates: Necromancy magic.

Power: You may use your bonus action to speak the command word (“Feed me!”), then make a ranged weapon attack with this dagger against a target within 30 feet. On a hit, the creature has disadvantage on its next attack roll. In addition, blood sprays towards you from the wound, granting you temporary hit points equal to the damage dealt. These temporary hit points vanish after you complete a short rest or long rest. The dagger then returns to your hand. Constructs, oozes, plants, undead, and creatures without blood are immune to this effect.