Malfeasance

[Requires Attunement]
Hit Points lost to this weapon can be regained only through a short or long rest.
At the start of each of the wounded creature's turns, it takes 1d4 necrotic damage for each wound, and can then make a DC 15 Con save ending the effect. If a wounded creature starts its turn with 5 or more wounds from this weapon, it must make a DC 15 Con save or take 10d4 necrotic damage. If this reduces the target to 50 Hit Points or fewer, it explodes, killing it instantly.