Powerbalance

Whenever an opponent casts a spell, you may reveal the top card of your library. If you do, you may cast that card without paying its mana cost if the two spells have the same mana value.

Pain Distributor

Menace
Whenever a player casts their first spell each turn, they create a Treasure token.
Whenever an artifact an opponent controls is put into a graveyard from the battlefield, this creature deals 1 damage to that player.

Spiteful Prankster

During your turn, this creature has first strike.
Whenever another creature dies, this creature deals 1 damage to target player or planeswalker.

Heap Gate

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{1}, {T}, Tap an untapped Gate you control: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Gorgon Flail

Equipped creature gets +1/+1 and has deathtouch. (Any amount of damage it deals to a creature is enough to destroy that creature.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Gibbering Fiend

When this creature enters, it deals 1 damage to each opponent.
Delirium — At the beginning of each opponent's upkeep, if there are four or more card types among cards in your graveyard, this creature deals 1 damage to that player.

Gateway Plaza

This land enters tapped.
When this land enters, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

Gond Gate

Gates you control enter untapped.
{T}: Add {C}.
{T}: Add one mana of any color that a Gate you control could produce.

Circle of Flame

Whenever a creature without flying attacks you or a planeswalker you control, this enchantment deals 1 damage to that creature.

Flame Fusillade

Until end of turn, permanents you control gain "{T}: This permanent deals 1 damage to any target."

Mana Clash

You and target opponent each flip a coin. Mana Clash deals 1 damage to each player whose coin comes up tails. Repeat this process until both players' coins come up heads on the same flip.

Island

Cliffgate

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

Brimstone Trebuchet

Defender, reach
{T}: This creature deals 1 damage to each opponent.
Whenever a Knight you control enters, untap this creature.

Blazing Volley

Blazing Volley deals 1 damage to each creature your opponents control.

Crackling Perimeter

Tap an untapped Gate you control: This enchantment deals 1 damage to each opponent.

Torture Pit

If a source you control would deal noncombat damage to an opponent, it deals that much damage plus 2 instead.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Spiked Corridor

When you unlock this door, create three 1/1 red Devil creature tokens with "When this token dies, it deals 1 damage to any target."
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Spiked Corridor // Torture Pit

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Talon Gates of Madara

When this land enters, up to one target creature phases out.
{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{4}: Put this card from your hand onto the battlefield.

Ghyrson Starn, Kelermorph

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Three Autostubs — Whenever another source you control deals exactly 1 damage to a permanent or player, Ghyrson Starn deals 2 damage to that permanent or player.

Hunter's Blowgun

Equipped creature gets +1/+1.
Equipped creature has deathtouch during your turn. Otherwise, it has reach.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Shivan Gorge

{T}: Add {C}.
{2}{R}, {T}: Shivan Gorge deals 1 damage to each opponent.

Kyren Negotiations

Tap an untapped creature you control: This enchantment deals 1 damage to target player or planeswalker.

Gorgon's Head

Equipped creature has deathtouch.
Equip {2}

Thermo-Alchemist

Defender
{T}: This creature deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap this creature.

Sapphire Medallion

Blue spells you cast cost {1} less to cast.

Grafted Exoskeleton

Equipped creature gets +2/+2 and has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Grafted Exoskeleton becomes unattached from a permanent, sacrifice that permanent.
Equip {2}

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.'"

Baldur's Gate

{T}: Add {C}.
{2}, {T}: Add X mana of any one color, where X is the number of other Gates you control.

Manabarbs

Whenever a player taps a land for mana, this enchantment deals 1 damage to that player.

Tibalt, Rakish Instigator

Your opponents can't gain life.
−2: Create a 1/1 red Devil creature token with "When this token dies, it deals 1 damage to any target."

Defiler of Instinct

First strike
As an additional cost to cast red permanent spells, you may pay 2 life. Those spells cost {R} less to cast if you paid life this way. This effect reduces only the amount of red mana you pay.
Whenever you cast a red permanent spell, this creature deals 1 damage to any target.

Aether Sting

Whenever an opponent casts a creature spell, this enchantment deals 1 damage to that player.

Izzet Guildgate

This land enters tapped.
{T}: Add {U} or {R}.

End the Festivities

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

Repercussion

Whenever a creature is dealt damage, this enchantment deals that much damage to that creature's controller.

Battle Strain

Whenever a creature blocks, this enchantment deals 1 damage to that creature's controller.

Nettle Drone

Devoid (This card has no color.)
{T}: This creature deals 1 damage to each opponent.
Whenever you cast a colorless spell, untap this creature.

Ruby Medallion

Red spells you cast cost {1} less to cast.

Lightning-Rig Crew

{T}: This creature deals 1 damage to each opponent.
Whenever you cast a Pirate spell, untap this creature.

Sol Ring

Immolation Shaman

Whenever an opponent activates an ability of an artifact, creature, or land that isn't a mana ability, this creature deals 1 damage to that player.
{3}{R}{R}: This creature gets +3/+3 and gains menace until end of turn.

Saheeli Rai

+1: Scry 1. Saheeli Rai deals 1 damage to each opponent.
−2: Create a token that's a copy of target artifact or creature you control, except it's an artifact in addition to its other types. That token gains haste. Exile it at the beginning of the next end step.
−7: Search your library for up to three artifact cards with different names, put them onto the battlefield, then shuffle.

Quicksilver Dagger

Enchant creature
Enchanted creature has "{T}: This creature deals 1 damage to target player or planeswalker. You draw a card."

Shattered Yard

At the beginning of your end step, this Room deals 1 damage to each opponent.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Glassworks

When you unlock this door, this Room deals 4 damage to target creature an opponent controls.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Glassworks // Shattered Yard

Mountain

Razorkin Needlehead

This creature has first strike during your turn.
Whenever an opponent draws a card, this creature deals 1 damage to them.

Roiling Vortex

At the beginning of each player's upkeep, this enchantment deals 1 damage to them.
Whenever a player casts a spell, if no mana was spent to cast that spell, this enchantment deals 5 damage to that player.
{R}: Your opponents can't gain life this turn.

Tectonic Hazard

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

The Red Terror

Advanced Species — Whenever a red source you control deals damage to one or more permanents and/or players, put a +1/+1 counter on The Red Terror.

Staff of Nin

At the beginning of your upkeep, draw a card.
{T}: This artifact deals 1 damage to any target.

Resurrection Orb

Equipped creature has lifelink.
Whenever equipped creature dies, return that card to the battlefield under its owner's control at the beginning of the next end step.
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

Shadowspear

Equipped creature gets +1/+1 and has trample and lifelink.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Equip {2}

Sigil of Sleep

Enchant creature
Whenever enchanted creature deals damage to a player, return target creature that player controls to its owner's hand.

Basilisk Collar

Equipped creature has deathtouch and lifelink. (Any amount of damage it deals to a creature is enough to destroy it. Damage dealt by this creature also causes you to gain that much life.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Goblin Sharpshooter

This creature doesn't untap during your untap step.
Whenever a creature dies, untap this creature.
{T}: This creature deals 1 damage to any target.

Hissing Iguanar

Whenever another creature dies, you may have this creature deal 1 damage to target player or planeswalker.

Basilisk Gate

{T}: Add {C}.
{2}, {T}: Target creature gets +X/+X until end of turn, where X is the number of Gates you control. Activate only as a sorcery.

Barbed Wire

At the beginning of each player's upkeep, this artifact deals 1 damage to that player.
{2}: Prevent the next 1 damage that would be dealt by this artifact this turn.

Gleeful Arsonist

Whenever an opponent casts a noncreature spell, this creature deals damage equal to its power to that player.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Scouring Sands

Scouring Sands deals 1 damage to each creature your opponents control. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Charisma

Enchant creature
Whenever enchanted creature deals damage to a creature, gain control of the other creature for as long as this Aura remains on the battlefield.

Unruly Catapult

Sea Gate

This land enters tapped.
As this land enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Will, Scholar of Frost

Instant and sorcery spells you cast cost {1} less to cast.
+1: Up to one target creature has base power and toughness 0/2 until your next turn.
−3: Draw two cards.
−7: Exile up to five target permanents. For each permanent exiled this way, its controller creates a 4/4 blue and red Elemental creature token.

Rowan, Scholar of Sparks

Instant and sorcery spells you cast cost {1} less to cast.
+1: Rowan deals 1 damage to each opponent. If you've drawn three or more cards this turn, she deals 3 damage to each opponent instead.
−4: You get an emblem with "Whenever you cast an instant or sorcery spell, you may pay {2}. If you do, copy that spell. You may choose new targets for the copy."

Rowan, Scholar of Sparks // Will, Scholar of Frost

Rampaging Ferocidon

Menace
Players can't gain life.
Whenever another creature enters, this creature deals 1 damage to that creature's controller.

Spear Spewer

Defender
{T}: This creature deals 1 damage to each player.

Teferi's Puzzle Box

At the beginning of each player's draw step, that player puts the cards in their hand on the bottom of their library in any order, then draws that many cards.

Fevered Visions

At the beginning of each player's end step, that player draws a card. If the player is your opponent and has four or more cards in hand, this enchantment deals 2 damage to that player.

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, this creature deals that much damage to target creature or planeswalker that player controls.

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}

Caltrops

Whenever a creature attacks, this artifact deals 1 damage to it.

Lobber Crew

Defender
{T}: This creature deals 1 damage to each opponent.
Whenever you cast a multicolored spell, untap this creature.

Sunshot Militia

Tap two untapped artifacts and/or creatures you control: This creature deals 1 damage to each opponent. Activate only as a sorcery.

Thran Portal

This land enters tapped unless you control two or fewer other lands.
As this land enters, choose a basic land type.
This land is the chosen type in addition to its other types.
Mana abilities of this land cost an additional 1 life to activate.