Bore into Oblivion

As additional cost to cast Bore into Oblivion,
exile X target artifacts and/or creatures you both
own and control.
Target opponent exiles the top X cards of their
library, then repeats this process two times. For
as long as those cards remain exiled, you may play
cards from among them and you may spend mana
as though it were mana of any color to cast cards
exiled this way.