Ugin, the Elder Dragon

Partner with Nicol Bolas, the Manipulator (When
this creature enters the battlefield, target player may
put Nicol Bolas, the Manipulator into their hand from
their library, then shuffle.)
Flying
Whenever Ugin, the Elder Dragon enters the battlefield, exile each colored permanent with converted mana cost equal to, or less than, the
amount of colored mana spent to cast it.