This is a blink mirror where your black cards — Thoughtseize, Overlord of the Balemurk, and Emperor of Bones — give you a meaningful edge in the grind, so protect your engine and attack theirs. High Noon is the key sideboard card: it shuts off their ability to Ephemerate at end of turn and follow up with another spell on their next turn, dramatically slowing their value generation. Mystical Dispute and the additional Consign to Memory copies let you fight over Teferi, Time Raveler and Quantum Riddler — Teferi in particular is the highest-impact threat since it locks off your instant-speed Ephemerates, so use Thoughtseize aggressively to pull it from their hand before they can resolve it. Flickerwisp is trimmed because it is the slowest blink engine piece and requires attacking to generate value, which is awkward in a creature-parity matchup. Fatal Push still covers Phelia and Guide of Souls, so you keep three, but Prismatic Ending and Boggart Trawler are dead weight here.