Ullbrecht, Thief of Cognizance

When Ullbrecht, Thief of Cognizance enters the
battlefield, for each other player, look at that
player's hand and choose a nonland card from it.
That player exiles that card.
You may cast spells exiled with Ullbrecht and
you may spend mana as though it were mana of
any color to do so.
Spells you cast that you don't own cost {2} less to
cast.