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.)

Kite Shield

Equipped creature gets +0/+3.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Case of the Burning Masks

When this Case enters, it deals 3 damage to target creature an opponent controls.
To solve — Three or more sources you controlled dealt damage this turn. (If unsolved, solve at the beginning of your end step.)
Solved — Sacrifice this Case: Exile the top three cards of your library. Choose one of them. You may play that card this turn.

Flame-Blessed Bolt

Flame-Blessed Bolt deals 2 damage to target creature or planeswalker. If that creature or planeswalker would die this turn, exile it instead.

Call In a Professional

Players can't gain life this turn. Damage can't be prevented this turn. Call In a Professional deals 3 damage to any target. (Shield counters don't prevent this damage as they're removed.)

Song of Totentanz

Create X 1/1 black Rat creature tokens with "This creature can't block." Creatures you control gain haste until end of turn.

Oasis Gardener

When Oasis Gardener enters, you gain 2 life.
{T}: Add one mana of any color.

Electric Revelation

As an additional cost to cast this spell, discard a card.
Draw two cards.
Flashback {3}{R} (You may cast this card from your graveyard for its flashback cost and any additional costs. Then exile it.)

Bomber Corps

Battalion — Whenever Bomber Corps and at least two other creatures attack, Bomber Corps deals 1 damage to any target.

Kiki-Jiki, Mirror Breaker

Haste
{T}: Create a token that's a copy of target nonlegendary creature you control, except it has haste. Sacrifice it at the beginning of the next end step.

Guardian Idol

Guardian Idol enters tapped.
{T}: Add {C}.
{2}: Guardian Idol becomes a 2/2 Golem artifact creature until end of turn.

Stonespeaker Crystal

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Stonespeaker Crystal: Exile any number of target players' graveyards. Draw a card.

Shiny Impetus

Enchant creature
Enchanted creature gets +2/+2 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
Whenever enchanted creature attacks, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Rending Flame

Rending Flame deals 5 damage to target creature or planeswalker. If that permanent is a Spirit, Rending Flame also deals 2 damage to that permanent's controller.

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.

Lacerate Flesh

Lacerate Flesh deals 4 damage to target creature. Create a number of Blood tokens equal to the amount of excess damage dealt to that creature this way. (They're artifacts with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Magda, the Hoardmaster

Whenever you commit a crime, create a tapped Treasure token. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)
Sacrifice three Treasures: Create a 4/4 red Scorpion Dragon creature token with flying and haste. Activate only as a sorcery.

Blaze

Prickly Pair

When Prickly Pair enters, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."

Imodane, the Pyrohammer

Whenever an instant or sorcery spell you control that targets only a single creature deals damage to that creature, Imodane deals that much damage to each opponent.

Krenko's Command

Create two 1/1 red Goblin creature tokens.

Burning Prophet

Whenever you cast a noncreature spell, Burning Prophet gets +1/+0 until end of turn, then scry 1.

Nahiri's Sacrifice

As an additional cost to cast this spell, sacrifice an artifact or creature with mana value X.
Nahiri's Sacrifice deals X damage divided as you choose among any number of target creatures.

Sawblade Scamp

Haste
Whenever you cast a noncreature spell, put an oil counter on Sawblade Scamp.
{T}, Remove an oil counter from Sawblade Scamp: It deals 1 damage to each opponent.

Thunder Salvo

Thunder Salvo deals X damage to target creature, where X is 2 plus the number of other spells you've cast this turn.

Daring Discovery

Up to three target creatures can't block this turn.
Discover 4. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Sticky Fingers

Enchant creature
Enchanted creature has menace and "Whenever this creature deals combat damage to a player, create a Treasure token." (It can't be blocked except by two or more creatures. The token is an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
When enchanted creature dies, draw a card.

Demon Bolt

Demon Bolt deals 4 damage to target creature or planeswalker.
Foretell {R} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Strangle

Strangle deals 3 damage to target creature or planeswalker.

Mechanized Warfare

If a red or artifact source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 1 instead.

Torch the Witness

Torch the Witness deals twice X damage to target creature. If excess damage was dealt to that creature this way, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Solphim, Mayhem Dominus

If a source you control would deal noncombat damage to an opponent or a permanent an opponent controls, it deals double that damage to that player or permanent instead.
{1}{R/P}{R/P}, Discard two cards: Put an indestructible counter on Solphim, Mayhem Dominus. ({R/P} can be paid with either {R} or 2 life.)

Light Up the Stage

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

Frantic Firebolt

Frantic Firebolt deals X damage to target creature, where X is 2 plus the number of cards in your graveyard that are instant cards, sorcery cards, and/or have an Adventure.

Devilish Valet

Trample, haste
Alliance — Whenever another creature you control enters, double Devilish Valet's power until end of turn.

Breeches, Eager Pillager

First strike
Whenever a Pirate you control attacks, choose one that hasn't been chosen this turn —
• Create a Treasure token.
• Target creature can't block this turn.
• Exile the top card of your library. You may play it this turn.

Trick Shot

Trick Shot deals 6 damage to target creature and 2 damage to up to one other target creature token.

Cut In

Cut In deals 4 damage to target creature.
Create a Young Hero Role token attached to up to one target creature you control. (If you control another Role on it, put that one into the graveyard. Enchanted creature has "Whenever this creature attacks, if its toughness is 3 or less, put a +1/+1 counter on it.")

Mountain

Captain Lannery Storm

Haste
Whenever Captain Lannery Storm attacks, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Whenever you sacrifice a Treasure, Captain Lannery Storm gets +1/+0 until end of turn.

Koth, Fire of Resistance

+2: Search your library for a basic Mountain card, reveal it, put it into your hand, then shuffle.
−3: Koth, Fire of Resistance deals damage to target creature equal to the number of Mountains you control.
−7: You get an emblem with "Whenever a Mountain you control enters, this emblem deals 4 damage to any target."

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Guttersnipe

Whenever you cast an instant or sorcery spell, Guttersnipe deals 2 damage to each opponent.

Ready to Rumble

Choose one —
• Ready to Rumble deals 5 damage to target creature or planeswalker.
• Destroy target artifact.

Galvanize

Galvanize deals 3 damage to target creature. If you've drawn two or more cards this turn, Galvanize deals 5 damage to that creature instead.

Dogpile

Dogpile deals damage to any target equal to the number of attacking creatures you control.

Balor

Flying
Whenever Balor attacks or dies, choose one or more. Each mode must target a different player.
• Target opponent draws three cards, then discards three cards at random.
• Target opponent sacrifices a nontoken artifact.
• Balor deals damage to target opponent equal to the number of cards in their hand.

Flick a Coin

Flick a Coin deals 1 damage to any target. You create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Draw a card.

Witchstalker Frenzy

This spell costs {1} less to cast for each creature that attacked this turn.
Witchstalker Frenzy deals 5 damage to target creature.

Vengeful Tracker

Whenever an opponent sacrifices an artifact, Vengeful Tracker deals 2 damage to them.

Scorching Shot

Scorching Shot deals 5 damage to target creature.

Leyline of Lightning

If Leyline of Lightning is in your opening hand, you may begin the game with it on the battlefield.
Whenever you cast a spell, you may pay {1}. If you do, Leyline of Lightning deals 1 damage to target player or planeswalker.

Legion Warboss

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
At the beginning of combat on your turn, create a 1/1 red Goblin creature token. That token gains haste until end of turn and attacks this combat if able.

Torch Breath

This spell costs {2} less to cast if it targets a blue permanent.
This spell can't be countered.
Torch Breath deals X damage to target creature or planeswalker.

Tectonic Hazard

Tectonic Hazard deals 1 damage to each opponent and each creature they control.

Stensia Uprising

At the beginning of your end step, create a 1/1 red Human creature token. Then if you control exactly thirteen permanents, you may sacrifice Stensia Uprising. When you do, it deals 7 damage to any target.

Abrade

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

Bloodthirsty Blade

Equipped creature gets +2/+0 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
{1}: Attach Bloodthirsty Blade to target creature an opponent controls. Activate only as a sorcery.

Ebony Fly

Ebony Fly enters tapped.
{T}: Add {C}.
{4}: Roll a d6. Until end of turn, you may have Ebony Fly become an X/X Insect artifact creature with flying, where X is the result.
Whenever Ebony Fly attacks, another target attacking creature gains flying until end of turn.

Smite the Deathless

Smite the Deathless deals 3 damage to target creature. That creature loses indestructible until end of turn. If that creature would die this turn, exile it instead.

Shock

Demand Answers

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

Impact Tremors

Whenever a creature you control enters, Impact Tremors deals 1 damage to each opponent.

Raid Bombardment

Whenever a creature you control with power 2 or less attacks, Raid Bombardment deals 1 damage to the player or planeswalker that creature is attacking.