Emrakul, the Arisen One

This spell can't be countered.
When you cast this spell, take an extra turn after this one.
Flying, protection from noncreature spells, annihilator 4
Whenever Emrakul, the Arisen One is put into a graveyard from anywhere, destroy all colored creatures. They can't be regenerated. Then, each opponent shuffles all cards from his/her graveyard into their library.