Earthbreaker is a Unique Ring in Diablo IV Season 15. It drops from Bartuc, Lord of Chaos.
Unique power
Casts of Landslide leave behind Tectonic Spikes that deal [375-525] Physical damage over 2 seconds. Spawning a Landslide pillar within Tectonic Spikes has a [50-60]% chance to spawn two instead.
Affixes
+111 All Resist
+[1-3] to Landslide (1-3)
Where it drops
World drop (any difficulty, drop rate scales with Torment tier)
Dedicated drop: Bartuc, Lord of Chaos (Infernal Hordes, 666 Burning Aether; Boss Trophy: Chaotic Essence)
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)
Horadric Cube: Item Transmutation (Amalgamation) - 5x Chaotic Essence (Boss Trophy) rolls a Unique from this boss's pool; can roll Mythic quality with the 'Crafted' tag