Nima, Corrupted Balu

Menace, haste, devour 2

Whenever Nima, Corrupted Balu enters the battlefield or attacks, you may sacrifice any number
of nontoken permanents you own. For each
permanent sacrificed this way, put that many cards
from the top of your library into your graveyard.
You may cast cards put into your graveyard this
way. They cost {2} less to cast