Living End (and its Violent Outburst cascade backup) wins by suspending and then flashing back a critical mass of creatures from the graveyard, so the single most impactful card you can bring in is Grafdigger's Cage, which completely turns off their namesake Living End and Violent Outburst payoffs from ever entering play. Warping Wail's counter-sorcery mode directly stops a cascaded-into or hard-cast Living End before it resolves, giving you a second layer of interaction alongside Cage; its other modes are useful against their small creatures like Street Wraith or Oliphaunt tokens. Unholy Heat is cut because most of what actually threatens you here are the huge reanimated bodies (Waker of Waves 7/7, Oliphaunt 6/4, Generous Ent 5/7) that survive even a 6-damage delirium hit, so removal that trades for a Living End trigger is far more valuable than burn.