Rakdos Reanimator is nearly identical to UBG Reanimator in approach — they can kill on turn one through Thoughtseize backed by Reanimate or Shallow Grave into Griselbrand, and their post-board Stronghold Gambit and Show and Tell are specifically designed to bypass your countermagic. Daze is dead against their fast mana and comes out entirely, as does Edge of Autumn which cycles too slowly to matter. Dauthi Voidwalker is your best sideboard card here — a turn-two Dauthi with two black mana up exiles every creature they attempt to reanimate and shuts down the deck wholesale. Cling to Dust supplements the graveyard disruption at instant speed, and Fatal Push handles early Griselbrand activations that slip through. Lead with Thoughtseize and Inquisition of Kozilek to strip their combo pieces, then set up your own kill while holding disruption in hand.