Axerial, The Extractor

Trample, deathtouch
{t}: Look at the top seven cards of target
opponent's library, exile three of them face down,
then put the rest on the bottom of their library.
For as long as those cards remain exiled, you may
look at them, you may cast them, and you may
spend mana as though it was mana of any type to
cast those spells.
"The mind is like a fortress of stone: Its barriers are
tough, but can be broken to access the sweet rewards
inside."