Greaves of the Empty Tomb is a Unique Boots. It can only be used by Necromancers.
Effect

How to get Greaves of the Empty Tomb
You can farm this unique from . You can also use our handy Target Farming Tool to see which dungeon is best to farm this unique.Grigoire, The Galvanic Saint
"The massive door to my family's crypt, which had taken a dozen men to close, was thrown open. Had I known the horrors to come I never would have set foot inside!" -The Ebon Pages, Canto I, Verse VII