The Primordial Ruler

Flying, Trample, Menace
When this creature ETBs, remove from play all other nonland permanents, add +X/+0 where X is equal to the mana value of all removed permanents, and +0/+Y where
Y is equal to the toughness of all removed creatures.

If Thanatos, King of Magic is on the battlefield, or is cast, counter or destroy it, and then exile this card.
"My father was unmatched in power. And as long as my mother was alive, he could never die. Sacrifices had to be made for revenge. I WILL make him pay."