The Fifteenth Doctor

Whenever The Fifteenth Doctor enters or attacks, mill three cards. You may put an artifact card with mana value 2 or 3 from among them into your hand.
The first nonartifact spell you cast each turn has improvise. (Your artifacts can help cast that spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)

Sungrass Prairie

Horizon Canopy

{T}, Pay 1 life: Add {G} or {W}.
{1}, {T}, Sacrifice Horizon Canopy: Draw a card.

Rose Noble

Ward {2}
Whenever you cast a Doctor spell or creature spell with doctor's companion, draw a card.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Overgrown Farmland

Overgrown Farmland enters tapped unless you control two or more other lands.
{T}: Add {G} or {W}.

Scattered Groves

({T}: Add {G} or {W}.)
Scattered Groves enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

The Fourteenth Doctor

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.