Overkill is a Unique Two-Handed Mace in Diablo IV Season 15. It comes from Varshan (Lair Boss hoard - targeted drop); Any Lair Boss general unique pool / world drop at Torment (chance rises per Torment tier); Horadric Cube: Item Transmutation - Upgrade to Unique (Common base of same type + 1 Enhanced Primordial Dust + 10 Primordial Dust) rolls a random unique of that item category.
Unique power
Death Blow gains all side upgrades and deals [60.0 - 75.0]%[x] increased damage.
Affixes
Weapon Damage
+Ranks to Death Blow (1 - 3)
Where it drops
Varshan (Lair Boss hoard - targeted drop)
Any Lair Boss general unique pool / world drop at Torment (chance rises per Torment tier)
Horadric Cube: Item Transmutation - Upgrade to Unique (Common base of same type + 1 Enhanced Primordial Dust + 10 Primordial Dust) rolls a random unique of that item category