Whenever Bag End Porter attacks, it gets +X/+X until end of turn, where X is the number of legendary creatures you control.

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

Creatures you control have "Whenever one or more counters are put on this creature for the first time each turn, draw a card."

Alliance — Whenever another creature enters the battlefield under your control, choose one that hasn't been chosen this turn —

• Put a +1/+1 counter on Gala Greeters.

• Create a tapped Treasure token.

• You gain 2 life.

Each legendary creature you control gets +1/+1 for each other legendary creature you control.

, : Look at the top X cards of your library. You may reveal a legendary creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Woman Who Walked the Earth — When Martha Jones enters the battlefield, investigate. (Create a Clue token. It's an artifact with ", Sacrifice this artifact: Draw a card.")

Whenever you sacrifice a Clue, Martha Jones and up to one other target creature can't be blocked this turn.

Doctor's companion (You can have two commanders if the other is the Doctor.)

Rotating Fireplace enters the battlefield tapped with a time counter on it.

: Add an amount of equal to the number of time counters on Rotating Fireplace.

, : Time travel. 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.)