Necalli, Awakened

Whenever this creature transforms into Necalli,
Awakened, you may sacrifice another creature.
You gain life equal to that creature's toughness.
Necalli, Awakened, can't be blocked by creatures
without flying.
When Necalli, Awakened dies, return it to the
battlefield tapped as Necalli, Devourer.
"I am the true darkness. "