The format is Core Constructed, entry is $75, capped at 128 players
This is a great shell for the Grief / Ephemerate combo because it naturally has a lot of black cards and almost every creature is great to Ephemerate, with Archon of Cruelty in particular being a highlight, especially since your natural curve involves spending two mana to reanimate Archon of Cruelty on Turn 3, at which point you can protect it with Ephemerate, which should be game-ending
Having red in the color identity rather than black gives the deck a different feel from Zaxara
Cast a beast a turn or two ahead of schedule, swing, and watch the life totals tumble
Still, the card undoubtedly looks cool, and will probably be included in more gimmicky item deck builds
+1: Attach this Equipment to up to one target creature you control