Sarah Jane Smith

Whenever you cast a historic spell, investigate. This ability triggers only once each turn. (Artifacts, legendaries, and Sagas are historic. To investigate, create a Clue token. It’s an artifact with “, Sacrifice this artifact: Draw a card.”)
Doctor’s companion (You can have two commanders if the other is the Doctor.)

Gruff Triplets

Trample
When Gruff Triplets enters the battlefield, if it isn’t a token, create two tokens that are copies of it.
When Gruff Triplets dies, put a number of +1/+1 counters equal to its power on each creature you control named Gruff Triplets.

Feral Encounter

Look at the top five cards of your library. You may exile a creature card from among them. Put the rest on the bottom of your library in a random order. You may cast the exiled card this turn. At the beginning of the next combat phase this turn, target creature you control deals damage equal to its power to up to one target creature you don’t control.

Kellan’s Lightblades

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
Kellan’s Lightblades deals 3 damage to target attacking or blocking creature. If this spell was bargained, destroy that creature instead.

Defense of the Heart

At the beginning of your upkeep, if an opponent controls three or more creatures, sacrifice Defense of the Heart, search your library for up to two creature cards, put those cards onto the battlefield, then shuffle.

Bone Splinters

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

Geology Enthusiast

At the beginning of your end step, create a tapped Powerstone token. (It’s an artifact with “: Add . This mana can’t be spent to cast a nonartifact spell.”)
: Draw a card and put a +1/+1 counter on Geology Enthusiast.

Two-Headed Hellkite

Flying, menace, haste
Whenever Two-Headed Hellkite attacks, draw two cards.

Champions of Tyr

Flying
Double team
When Champions of Tyr enters the battlefield, you get a boon with “When you cast your next creature spell, that creature enters the battlefield with your choice of a +1/+1 counter, a flying counter, or a lifelink counter on it.”

Blood Petal Celebrant

Blood Petal Celebrant has first strike as long as it’s attacking.
When Blood Petal Celebrant dies, create a Blood token. (It’s an artifact with “, , Discard a card, Sacrifice this artifact: Draw a card.”)