Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Act of Treason

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and {T} this turn.)

Shock

Impulsive Pilferer

When this creature dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Encore {3}{R} ({3}{R}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Ahn-Crop Crasher

Haste (This creature can attack and {T} as soon as it comes under your control.)
You may exert this creature as it attacks. When you do, target creature can't block this turn. (An exerted creature won't untap during your next untap step.)

Trueheart Twins

You may exert this creature as it attacks. (It won't untap during your next untap step.)
Whenever you exert a creature, creatures you control get +1/+0 until end of turn.

Combat Celebrant

If this creature hasn't been exerted this turn, you may exert it as it attacks. When you do, untap all other creatures you control and after this phase, there is an additional combat phase. (An exerted creature won't untap during your next untap step.)

Mountain

Thriving Bluff

This land enters tapped. As it enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Norin, Swift Survivalist

Norin can't block.
Whenever a creature you control becomes blocked, you may exile it. You may play that card from exile this turn.

Battlefield Scavenger

You may exert this creature as it attacks. (It won't untap during your next untap step.)
Whenever you exert a creature, you may discard a card. If you do, draw a card.

Nef-Crop Entangler

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
You may exert this creature 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.)

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Glorybringer

Flying, haste
You may exert this creature as it attacks. When you do, it deals 4 damage to target non-Dragon creature an opponent controls. (An exerted creature won't untap during your next untap step.)

Anep, Vizier of Hazoret

Trample
You may exert Anep as it attacks. When you do, exile the top two cards of your library. Until the end of your next turn, you may play those cards. (An exerted creature won't untap during your next untap step.)