Rufus H., Rogue Virtuoso

Companion — Your starting deck contains only
blue and black cards, and land cards.
(If this card is your chosen companion, you may cast
it once from outside the game.)
When you cast your first blue spell each turn,
your creatures gain Hexproof and Unblockable
this turn.
When you cast your first black spell each turn,
exile the top card in target player's library. You
may cast that card for as long as it remains exiled.
Spend mana of any color to cast it.