Leyline of the Void can be in play turn zero and exiles any card that would be put into their graveyard, which denies graveyard-based value like Echo of Eons' flashback. Tormod's Crypt is a cheap, flexible answer that strips their graveyard proactively, before they can flash back Echo of Eons. Leyline and the Crypt do not stop Burning Wish or Beseech the Mirror from finding their combo pieces, since those spells fetch from outside the game or from the library. We trim the lower-impact Defense Grid, Pithing Needle, Expedition Map, Mystic Forge, and one Manifold Key, since this is a very fast combo matchup where graveyard hate matters far more than these slower or situational artifacts.