The Twelfth Doctor

The first spell you cast from anywhere other than your hand each turn has demonstrate. (When you cast that spell, you may copy it. If you do, choose an opponent to also copy it. A copy of a permanent spell becomes a token.)
Whenever you copy a spell, put a +1/+1 counter on The Twelfth Doctor.

Yasmin Khan

{T}: Exile the top card of your library. Until your next end step, you may play it.
Doctor's companion (You can have two commanders if the other is the Doctor.)