Barco, The Dimir Mage

{x}{u/b}{u/b}{u/b}, Create {x} 1/1 blue black skeleton pirate creature tokens. Sacrifice Barco, The Dimir Mage.
Dredge 3 (If you would draw a card, instead you may put exactly three cards from the top of your library into your graveyard. If you do, return this card from your graveyard ).