Cursed Horseshoe

Cursed Horseshoes can be found in the Vision of Stormwind during Horrific Visions Revisited. They will only appear while at least one Faceless Mask is equipped. There are four horseshoes in total—one in each district except the Dwarven District. Each collected horseshoe grants a stack of the following buff for the rest of the run:

Cursed Horseshoe — Perhaps these should be destroyed somewhere?

At four stacks of the buff (that is, after collecting all four horseshoes in a single run), they can be destroyed at the Forge at ^[63, 37] in the Dwarven District's blacksmithing area. Doing so will summon the Void-Forged Stallion, which drops the [Void-Forged Stallion's Reins].