Nef-Crop Entangler

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
You may exert Nef-Crop Entangler as it attacks. When you do, it gets +1/+2 until end of turn. (An exerted creature won't untap during your next untap step.)

Sentinel's Eyes

Enchant creature
Enchanted creature gets +1/+1 and has vigilance.
Escape—{W}, Exile two other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Rhet-Crop Spearmaster

You may exert Rhet-Crop Spearmaster as it attacks. When you do, it gets +1/+0 and gains first strike until end of turn. (An exerted creature won't untap during your next untap step.)

Journey to Nowhere

When Journey to Nowhere enters, exile target creature.
When Journey to Nowhere leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Brighthearth Banneret

Elemental spells and Warrior spells you cast cost {1} less to cast.
Reinforce 1—{1}{R} ({1}{R}, Discard this card: Put a +1/+1 counter on target creature.)

Plains

Herald of Dromoka

Vigilance
Other Warrior creatures you control have vigilance.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Tah-Crop Elite

Flying
You may exert Tah-Crop Elite as it attacks. When you do, creatures you control get +1/+1 until end of turn. (An exerted creature won't untap during your next untap step.)

Mountain

Thraben Inspector

When Thraben Inspector enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Emberhorn Minotaur

You may exert Emberhorn Minotaur as it attacks. When you do, it gets +1/+1 and gains menace until end of turn. (An exerted creature won't untap during your next untap step. A creature with menace can't be blocked except by two or more creatures.)

Wind-Scarred Crag

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {R} or {W}.

Khenra Scrapper

Menace
You may exert Khenra Scrapper as it attacks. When you do, it gets +2/+0 until end of turn. (An exerted creature won't untap during your next untap step.)

Marshaling Cry

Creatures you control get +1/+1 and gain vigilance until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)
Flashback {3}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Oketra's Avenger

You may exert Oketra's Avenger as it attacks. When you do, prevent all combat damage that would be dealt to it this turn. (An exerted creature won't untap during your next untap step.)