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.

I. AM. TALKING! — Whenever The Eleventh Doctor deals combat damage to a player, you may exile a card from your hand with a number of time counters on it equal to its mana value. If it doesn't have suspend, it gains suspend. {2}: Target creature with power 3 or less can't be blocked this turn.

When The First Doctor enters, search your library and/or graveyard for a card named TARDIS, reveal it, and put it into your hand. If you search your library this way, shuffle. Whenever you cast a spell with cascade, put a +1/+1 counter on target artifact or creature.

Paradox — Whenever you cast a spell from anywhere other than your hand, put a +1/+1 counter on target creature. Team TARDIS — At the beginning of your end step, untap each creature you control with a counter on it.

Whenever The Seventh Doctor attacks, choose a card in your hand. Defending player guesses whether that card's mana value is greater than the number of artifacts you control. If they guessed wrong, you may cast it without paying its mana cost. If you don't cast a spell this way, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

When you cast this spell, reveal the top fourteen cards of your library. Put all Doctor cards revealed this way into your graveyard and the rest on the bottom of your library in a random order. You may have The Fourteenth Doctor enter as a copy of a Doctor card in your graveyard that was put there from your library this turn. If you do, it gains haste until end of turn.

When The Fugitive Doctor enters, investigate. Whenever The Fugitive Doctor attacks, you may sacrifice a Clue. When you do, target instant or sorcery card in your graveyard gains flashback {2}{R}{G} until end of turn. (You may cast that card from your graveyard for its flashback cost. Then exile it.)

You may pay {0} rather than pay the cycling cost of the first card you cycle each turn. Whenever you draw your second card each turn, create a 2/2 red and white Dinosaur Cat creature token.

Whenever one or more other permanents phase out and whenever one or more other cards are put into exile from anywhere, put a time counter on The War Doctor. Whenever The War Doctor attacks, it deals damage equal to the number of time counters on it to any target. If a creature dealt damage this way would die this turn, exile it instead.

Allons-y! — Whenever you attack, exile cards from the top of your library until you exile a nonland card. Put three time counters on it. If it doesn't have suspend, it gains suspend. Timey-Wimey — {7}: Time travel three times. Activate only as a sorcery. (For each suspended card you own and each permanent you control with a time counter on it, you may add or remove a time counter. Then do it two more times.)

Trample The Third Doctor gets +1/+1 for each noncreature token you control. When The Third Doctor enters, create your choice of a Clue token, a Food token, or a Treasure token.