Riders of the Mark

Affinity for Humans (This spell costs {1} less to cast for each Human you control.)
Trample, haste
At the beginning of your end step, if this creature attacked this turn, return it to its owner's hand. If you do, create a number of 1/1 white Human Soldier creature tokens equal to its toughness.

Insight Engine

{2}, {T}: Put a charge counter on this artifact, then draw a card for each charge counter on it.

Tortured Existence

{B}, Discard a creature card: Return target creature card from your graveyard to your hand.

Cairn Wanderer

Changeling (This card is every creature type.)
As long as a creature card with flying is in a graveyard, this creature has flying. The same is true for fear, first strike, double strike, deathtouch, haste, landwalk, lifelink, protection, reach, trample, shroud, and vigilance.

Valakut Stoneforge

Valakut Awakening

Put any number of cards from your hand on the bottom of your library, then draw that many cards plus one.

Valakut Awakening // Valakut Stoneforge

Saheeli, the Gifted

+1: Create a 1/1 colorless Servo artifact creature token.
+1: The next spell you cast this turn has affinity for artifacts. (It costs {1} less to cast for each artifact you control as you cast it.)
−7: For each artifact you control, create a token that's a copy of it. Those tokens gain haste. Exile those tokens at the beginning of the next end step.
Saheeli, the Gifted can be your commander.

Sarkhan's Triumph

Search your library for a Dragon creature card, reveal it, put it into your hand, then shuffle.

Basal Sliver

All Slivers have "Sacrifice this permanent: Add {B}{B}."

Alena, Kessig Trapper

First strike
{T}: Add an amount of {R} equal to the greatest power among creatures you control that entered this turn.
Partner (You can have two commanders if both have partner.)