Bjornfang's Tusks is a Unique Gloves in Diablo IV Season 15. It comes from World drop (any difficulty, drop rate scales with Torment tier); Horadric Cube: Item Transmutation (Upgrade to Unique) - Common item of the same slot + 1 Enhanced Primordial Dust + 10 Primordial Dust (random Unique of that slot).
Unique power
Cataclysm's lightning strikes now prioritize enemies. While Cataclysm is active, you gain unlimited Spirit and deal [40-100]%[x] increased damage.
Affixes
+[1-2] to Endless Tempest (1-2)
+[57.0-75.0]% Non-Physical Damage (57-75%)
+[6.0-8.0]% Critical Strike Chance (6-8%)
+[2-3] to Core Skills (2-3)
Where it drops
World drop (any difficulty, drop rate scales with Torment tier)
Horadric Cube: Item Transmutation (Upgrade to Unique) - Common item of the same slot + 1 Enhanced Primordial Dust + 10 Primordial Dust (random Unique of that slot)