House Dimir

Cards in your hand have Transmute {1}{u}{b}
(They have {1}{u}{b}, Discard this card: Search your library for a card with the same converted mana cost
as this card, reveal it, and put it into your hand.
Shuffle your library. Activate this ability only at a
time you could cast a sorcery.)
{3}{u}{b}: You gain control of target creature with converted mana cost that is less than your
devotion to black and blue. Surveil 1.