Wall of Mourning

Card advantage that scales to the pod, held hostage by a board condition you have to actively maintain. The entry trigger banks a hidden reserve sized to your opponent count, so at a crowded table this Wall is quietly sitting on three or four cards; the payout comes one at a time, each end step, only while you hold three creatures with distinct powers. That coven clause is the whole tension: the reserve is real, but the drip depends on you keeping a board diverse enough to unlock it, and a sweeper doesn't just kill the Wall, it turns off the engine and strands whatever cards are still exiled. A 0/4 with defender is doing exactly what a defensive value piece should do here, holding the ground while the exile pile pays out behind it, and the design leans on the multiplayer math to make a two-mana body worth the slot. What makes the clause interesting is where it sits in white's toolkit: white rarely draws cards outright, so it launders advantage through conditional recursion and delayed value instead, and pinning that value to a coven check ties the card-draw rate to how wide and varied you're willing to build rather than to raw mana. The result is a slow engine that rewards a go-wide creature base and punishes durdling with a single removal spell.