Living End is a suspend-based cascade combo that relies on cascade spells like Shardless Agent and Violent Outburst; Consign to Memory can counter the cascade triggered abilities or the suspend triggered ability, making it your single best sideboard card here. Rest in Peace exiles all graveyards and keeps cards out of them, completely shutting down their reanimation plan. Day's Undoing is cut since drawing seven cards gives them a fresh hand to find more cyclers and cascade spells, and Prismatic Ending is trimmed since it can't interact with the triggered ability that actually wins them the game.