Spill the Blood, Fuel the Rage

Convoke
Whenever enchanted creature deals damage, the creature's owner sacrifices a land. If enchanted creature is killed, deal {x} damage to the creature's owner, {x} being half the number of lands
sacrificed by this card.
Spilling blood is the most dangerous and foolish thing
you could do in a fight with a vampire. Every drop of
blood they see only strengthen's their resolve, and
makes them more vicious and more violent. This is
why they are dangerous