Carrion War Pick

Weapon (war pick), uncommon

If you hit a creature that is missing any of its hit points using this magic weapon, its damage die becomes a d10 for the attack, and it deals necrotic damage instead of piercing. Furthermore, when you slay a Small or larger living creature with this weapon, you immediately gain 1d10 temporary hit points; you lose these hit points early if you're no longer holding the weapon.

The hooded man remained hunched over in the dark. Beneath him rest a body, now still, and in his hand he clutched a sickly weapon. Red ichor dripped from its pointed end.
Guards accosted the man before long, which turned violent of course. One after another, more bodies were added to the pile, and weapon's point remained glistening and crimson.
The man remained perched there, like the vulture he was, hungering for more.