Giant Cindermaw

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Players can't gain life.

Phoenix Chick

Flying, haste
This creature can't block.
Whenever you attack with three or more creatures, you may pay {R}{R}. If you do, return this card from your graveyard to the battlefield tapped and attacking with a +1/+1 counter on it.

Skewer the Critics

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Skewer the Critics deals 3 damage to any target.

End the Festivities

End the Festivities deals 1 damage to each opponent and each creature and planeswalker they control.

Bloodrage Brawler

When this creature enters, discard a card.

Bitter Reunion

When this enchantment enters, you may discard a card. If you do, draw two cards.
{1}, Sacrifice this enchantment: Creatures you control gain haste until end of turn.

Sardian Cliffstomper

As long as it's your turn and you control four or more Mountains, this creature gets +X/+0, where X is the number of Mountains you control.

Anax, Hardened in the Forge

Anax's power is equal to your devotion to red. (Each {R} in the mana costs of permanents you control counts toward your devotion to red.)
Whenever Anax or another nontoken creature you control dies, create a 1/1 red Satyr creature token with "This token can't block." If the creature had power 4 or greater, create two of those tokens instead.

Reinforced Ronin

Haste
At the beginning of your end step, return this creature to its owner's hand.
Channel — {1}{R}, Discard this card: Draw a card.

Shock

Slaying Fire

Slaying Fire deals 3 damage to any target.
Adamant — If at least three red mana was spent to cast this spell, it deals 4 damage instead.

Rigging Runner

First strike
Raid — This creature enters with a +1/+1 counter on it if you attacked this turn.

Riveteers Requisitioner

When this creature dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Blitz {2}{R} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Thrill of Possibility

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

Battle Cry Goblin

{1}{R}: Goblins you control get +1/+0 and gain haste until end of turn.
Pack tactics — Whenever this creature attacks, if you attacked with creatures with total power 6 or greater this combat, create a 1/1 red Goblin creature token that's tapped and attacking.

Bloody Betrayal

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. Create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")