Bane of Ahjad-Den is a Unique Gloves in Diablo IV Season 15. It drops from Harbinger of Hatred.
Unique power
While channeling Whirlwind, you now periodically hurl out a Mighty Throw that deals [75.0 - 90.0]%[x] increased damage.
Affixes
Physical Damage (Greater Affix on one guide listing) (+14.0 - 24.0%)
Lucky Hit Chance (per one guide, up to 20%)
Where it drops
Harbinger of Hatred (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