Screaming Nemesis

Haste
Whenever this creature is dealt damage, it deals that much damage to any other target. If a player is dealt damage this way, they can't gain life for the rest of the game.

Karplusan Forest

{T}: Add {C}.
{T}: Add {R} or {G}. This land deals 1 damage to you.

Manifold Mouse

Offspring {2} (You may pay an additional {2} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
At the beginning of combat on your turn, target Mouse you control gains your choice of double strike or trample until end of turn.

Monastery Swiftspear

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Hired Claw

Whenever you attack with one or more Lizards, this creature deals 1 damage to target opponent.
{1}{R}: Put a +1/+1 counter on this creature. Activate only if an opponent lost life this turn and only once each turn.

Thornspire Verge

{T}: Add {R}.
{T}: Add {G}. Activate only if you control a Mountain or a Forest.

Monstrous Rage

Target creature gets +2/+0 until end of turn. Create a Monster Role token attached to it. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1 and has trample.)

Heartfire Hero

Valiant — Whenever this creature becomes the target of a spell or ability you control for the first time each turn, put a +1/+1 counter on it.
When this creature dies, it deals damage equal to its power to each opponent.

Copperline Gorge

This land enters tapped unless you control two or fewer other lands.
{T}: Add {R} or {G}.

Emberheart Challenger

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Valiant — Whenever this creature becomes the target of a spell or ability you control for the first time each turn, exile the top card of your library. Until end of turn, you may play that card.

Burn Together

Target creature you control deals damage equal to its power to any other target. Then sacrifice it.

Callous Sell-Sword

This creature enters with a +1/+1 counter on it for each creature that died under your control this turn.

Callous Sell-Sword // Burn Together

Mountain

Turn Inside Out

Target creature gets +3/+0 until end of turn. When it dies this turn, manifest dread. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)

Restless Ridgeline

This land enters tapped.
{T}: Add {R} or {G}.
{2}{R}{G}: This land becomes a 3/4 red and green Dinosaur creature until end of turn. It's still a land.
Whenever this land attacks, another target attacking creature gets +2/+0 until end of turn. Untap that creature.

Giant Growth

Target creature gets +3/+3 until end of turn.

Rockface Village

{T}: Add {C}.
{T}: Add {R}. Spend this mana only to cast a creature spell.
{R}, {T}: Target Lizard, Mouse, Otter, or Raccoon you control gets +1/+0 and gains haste until end of turn. Activate only as a sorcery.

Slickshot Show-Off

Flying, haste
Whenever you cast a noncreature spell, this creature gets +2/+0 until end of turn.
Plot {1}{R} (You may pay {1}{R} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)