Opposite Day Ring

Opposite Day looks like a "fat ring" studded with five small jewels that glow ominously like tiny Soul Crystals. When the wearer is struck by a powerful spell, the ring activates: one of the jewels burns out (or explodes or disappears), and the spell rebounds at the caster. The ring can only be used five times.[1]

References

  1. Dinniman, Matt. The Butcher's Masquerade (Chapter 47)