Jace, Multiverse Architect

At the beginning of combat on each opponent's turn, they may pay {2}. If they don't, creatures they control can't attack Jaces you control this turn.

+1: Draw two cards, then put a card from your hand on the bottom of your library.

−3: Exile another target planeswalker or creature you control. Reveal cards from the top of your library until you reveal a creature or planeswalker card. Put that card onto the battlefield and the rest on the bottom of your library in a random order.

Jace, Multiverse Architect can be your commander.