Koth of the Hammer

+1: Untap target Mountain. It becomes a 4/4 red Elemental creature until end of turn. It's still a land.
−2: Add {R} for each Mountain you control.
−5: You get an emblem with "Mountains you control have '{T}: This land deals 1 damage to any target.'"

Angrath's Marauders

If a source you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Network Terminal

{T}: Add one mana of any color.
{1}, {T}, Tap another untapped artifact you control: Draw a card, then discard a card.

Gratuitous Violence

If a creature you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Component Pouch

{T}, Remove a component counter from Component Pouch: Add two mana of different colors.
{T}: Roll a d20.
1—9 | Put a component counter on Component Pouch.
10—20 | Put two component counters on Component Pouch.

Mountain

Stone of Erech

If a creature an opponent controls would die, exile it instead.
{2}, {T}, Sacrifice Stone of Erech: Exile target player's graveyard. Draw a card.

Puppet Strings

{2}, {T}: You may tap or untap target creature.

Dictate of the Twin Gods

Flash
If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Injury

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Injury deals 2 damage to target creature and 2 damage to target player or planeswalker.

Insult

Damage can't be prevented this turn. If a source you control would deal damage this turn, it deals double that damage instead.

Insult // Injury

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Curse of Bloodletting

Enchant player
If a source would deal damage to enchanted player, it deals double that damage to that player instead.

Fire Diamond

Fire Diamond enters tapped.
{T}: Add {R}.

Intelligence Bobblehead

{T}: Add one mana of any color.
{5}, {T}: Draw X cards, where X is the number of Bobbleheads you control.

Sting, the Glinting Dagger

Equipped creature gets +1/+1 and has haste.
At the beginning of each combat, untap equipped creature.
Equipped creature has first strike as long as it's blocking or blocked by a Goblin or Orc.
Equip {2}

Mana Geode

When Mana Geode enters, scry 1.
{T}: Add one mana of any color.

Desperate Gambit

Choose a source you control and flip a coin. If you win the flip, the next time that source would deal damage this turn, it deals double that damage instead. If you lose the flip, the next time it would deal damage this turn, prevent that damage.

Manakin

Iron Myr

Coalition Relic

{T}: Add one mana of any color.
{T}: Put a charge counter on Coalition Relic.
At the beginning of your first main phase, remove all charge counters from Coalition Relic. Add one mana of any color for each charge counter removed this way.

Embereth Blaze

Embereth Blaze deals 2 damage to any target. (Then exile this card. You may cast the enchantment later from exile.)

Virtue of Courage

Whenever a source you control deals noncombat damage to an opponent, you may exile that many cards from the top of your library. You may play those cards this turn.

Virtue of Courage // Embereth Blaze

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Seething Song

Hematite Talisman

Whenever a player casts a red spell, you may pay {3}. If you do, untap target permanent.

Clay Golem

{6}, Roll a d8: Monstrosity X, where X is the result. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.)
Berserk — When Clay Golem becomes monstrous, destroy target permanent.

Glittering Stockpile

{T}: Add {R}. Put a stash counter on Glittering Stockpile.
{T}, Sacrifice Glittering Stockpile: Add X mana of any one color, where X is the number of stash counters on Glittering Stockpile.

Heartless Hidetsugu

{T}: Heartless Hidetsugu deals damage to each player equal to half that player's life total, rounded down.

Inherited Envelope

When Inherited Envelope enters, the Ring tempts you.
{T}: Add one mana of any color.

Wildfire Elemental

Whenever an opponent is dealt noncombat damage, creatures you control get +1/+0 until end of turn.

Firemind Vessel

Firemind Vessel enters tapped.
{T}: Add two mana of different colors.

Cultivator's Caravan

{T}: Add one mana of any color.
Crew 3 (Tap any number of creatures you control with total power 3 or more: This Vehicle becomes an artifact creature until end of turn.)

Alloy Myr

Torbran, Thane of Red Fell

If a red source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 2 instead.

Threaten

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

Manalith

Overblaze

Each time target permanent would deal damage to a permanent or player this turn, it deals double that damage to that permanent or player instead.
Splice onto Arcane {2}{R}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Fountain of Ichor

{T}: Add one mana of any color.
{3}: Fountain of Ichor becomes a 3/3 Dinosaur artifact creature until end of turn.

Heraldic Banner

As Heraldic Banner enters, choose a color.
Creatures you control of the chosen color get +1/+0.
{T}: Add one mana of the chosen color.

Chandra's Incinerator

This spell costs {X} less to cast, where X is the total amount of noncombat damage dealt to your opponents this turn.
Trample
Whenever a source you control deals noncombat damage to an opponent, Chandra's Incinerator deals that much damage to target creature or planeswalker that player controls.

Isengard Unleashed

Damage can't be prevented this turn. If a source you control would deal damage this turn to an opponent or a permanent an opponent controls, it deals triple that damage instead.
Flashback {4}{R}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)