Mister Sinister, Genemaster

When Mister Sinister, Genemaster enters the
battlefield, if you cast it, tap any number of other
creatures you control. Search your library or
graveyard with a creature card with converted
mana cost of X or less and put it onto the
battlefield tapped, where X is the combined
converted mana cost of those creatures.
Exile four cards from your hand: Return Mister
Sinister, Genemaster from your graveyard
to your hand.