Alduin, The World Eater

Flying, Indestructible, Menace
Alduin, The World Eater's mana cost is reduced
by {2} for every Dragon in your graveyard.
Whenever Alduin, The World Eater enters
the battlefield, your opponent(s) sacrifice each creature they control.
During your untap phase, return target Dragon
from your graveyard to the battlefield.
"Daar lein los dii! (The World is Mine!)"—
Alduin, Son of Akatosh