Penitent Greaves is a Unique Boots in Diablo IV Season 15 for All classes. It comes from General Unique Pool; General Unique Pool - every Lair Boss (Initiate, Greater, Exalted, Belial) can drop it in addition to their dedicated table.
Unique power
You are permanently Unhindered and leave behind a trail of frost that Chills enemies. Your Chill effects cause enemies to take [10 - 15]%[x] increased damage from you.
Affixes
Primary Core Stat
Movement Speed
Where it drops
General Unique Pool
General Unique Pool - every Lair Boss (Initiate, Greater, Exalted, Belial) can drop it in addition to their dedicated table