100,000 Steps is a Unique Boots in Diablo IV Season 15. It drops from Varshan (Echo of Varshan).
Unique power
Ground Stomp's damage is increased by [20.0 - 25.0]%[x] plus an additional amount based on the distance traveled since the last casted Ground Stomp's, up to [80.0 - 100.0]%[x].
Affixes
Strength
+Ranks to Ground Stomp (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