Mordenkainen's Lost Notebook
5-level Necromancy
You touch a bone or skull and cause it to glow with a silver-grey radiance. You may then use your action to throw the bone or skull up to 60 feet at a creature you can see. Make a ranged spell attack. On a hit, the object’s radiance is transferred to the target. For the duration, the creature can’t regain hit points or benefit from regeneration from any source until the spell ends.