Flying {1}{B}, Exile Sengir Nosferatu: Create a 1/2 black Bat creature token with flying. It has "{1}{B}, Sacrifice this creature: Return an exiled card named Sengir Nosferatu to the battlefield under its owner's control."

When Bat Colony enters the battlefield, create a 1/1 black Bat creature token with flying for each mana from a Cave spent to cast it. Whenever a Cave enters the battlefield under your control, put a +1/+1 counter on target creature you control.

{T}: Add {C}. {1}, {T}, Sacrifice Promising Vein: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Calamitous Cave-In deals X damage to each creature and each planeswalker, where X is the number of Caves you control plus the number of Cave cards in your graveyard.