Anya, of the Dunes

Reach
Whenever Anya, of the Dunes, you may sacrifice
a land. If you do, search your library for a Desert
and put it onto the battlefield.
Threshold — {w}{w}, {t}: Anya, of the Dunes deals
damage to target attacking or blocking creature
equal to the number of deserts you control.
Activate only if seven or more cards are in your graveyard.