Orakh, Sprawling Necropolis

When Orakh, Sprawling Necropolis enters the
battlefield, create a number of 1/1 black
Vampire creature tokens equal to your devotion
to black.
{t}: Add {b}.
{2}, {t}, Pay 1 life: Target creature you control
becomes a Swamp with "{t}: Add {b} to your
mana pool" and loses all other card types and abilities.