Mithrix, the King of Nothing

{u}{3}: Search your Library for one "Collective" permanent and put it into play tapped.
{b}{b}{1}{t}: Deal damage to any target equal to the number of "Collective" permanents you control.
When Mithrix blocks or is targeted with a spell, you may pay {x}, where X is the converted mana cost of the attacking creature or spell. During your end step, if Mithrix was sent to your Graveyard during your turn, destroy up to X lands.