Relic of Progenitus can exile their graveyard in response to Sneaky Snacker's third-draw trigger so it never returns to the battlefield, and it also turns off Faithless Looting's flashback. It does nothing against madness, since discarded madness cards go to exile rather than the graveyard. Mana Tithe taxes their curve, disrupting Alms of the Vein, Vampire's Kiss, or a key Fiery Temper. Salt Road Packbeast is too slow against this fast burn-aggro clock and comes out, since affinity for creatures doesn't make it cheap enough early. Keep the low curve and Dispatch to pressure them back while playing around Lightning Bolt and Fiery Temper on our small creatures.