Yurlok of Scorch Thrash

Vigilance
A player losing unspent mana causes that player to lose that much life.
{1}, {T}: Each player adds {B}{R}{G}.

Kaervek the Merciless

Whenever an opponent casts a spell, Kaervek deals damage equal to that spell's mana value to any target.

Horizon Stone

If you would lose unspent mana, that mana becomes colorless instead.

Gruul Signet

Sol Ring

Lavalanche

Lavalanche deals X damage to target player or planeswalker and each creature that player or that planeswalker's controller controls.

Tangleroot

Whenever a player casts a creature spell, that player adds {G}.

Jaya's Immolating Inferno

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Jaya's Immolating Inferno deals X damage to each of up to three targets.

Veteran Explorer

When this creature dies, each player may search their library for up to two basic land cards, put them onto the battlefield, then shuffle.

Hurricane

Hurricane deals X damage to each creature with flying and each player.

Hydra Broodmaster

{X}{X}{G}: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.)
When this creature becomes monstrous, create X X/X green Hydra creature tokens.

Prevent all combat damage that would be dealt this turn.

Genesis Hydra

When you cast this spell, reveal the top X cards of your library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield. Then shuffle the rest into your library.
This creature enters with X +1/+1 counters on it.

Bounty Board

{T}: Add one mana of any color.
{1}, {T}: Put a bounty counter on target creature. Activate only as a sorcery.
Whenever a creature with a bounty counter on it dies, each of its controller's opponents draws a card and gains 2 life.

Stonecoil Serpent

Reach, trample, protection from multicolored
This creature enters with X +1/+1 counters on it.

Citadel of Pain

At the beginning of each player's end step, this enchantment deals X damage to that player, where X is the number of untapped lands they control.

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
This artifact enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on this artifact.

Mana Cache

At the beginning of each player's end step, put a charge counter on this enchantment for each untapped land that player controls.
Remove a charge counter from this enchantment: Add {C}. Any player may activate this ability but only during their turn before the end step.

Victory Chimes

Untap this artifact during each other player's untap step.
{T}: A player of your choice adds {C}.

Gemstone Array

{2}: Put a charge counter on this artifact.
Remove a charge counter from this artifact: Add one mana of any color.

Font of Fertility

{1}{G}, Sacrifice this enchantment: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Sword of the Paruns

As long as equipped creature is tapped, tapped creatures you control get +2/+0.
As long as equipped creature is untapped, untapped creatures you control get +0/+2.
{3}: You may tap or untap equipped creature.
Equip {3}

Svella, Ice Shaper

{3}, {T}: Create a colorless snow artifact token named Icy Manalith with "{T}: Add one mana of any color."
{6}{R}{G}, {T}: Look at the top four cards of your library. You may cast a spell from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.

Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Fire Diamond

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

Humble Defector

{T}: Draw two cards. Target opponent gains control of this creature. Activate only during your turn.

Exocrine

Ravenous (This creature enters with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.)
Bio-plasmic Barrage — When this creature enters, it deals X damage to each player and each other creature.

Zhur-Taa Ancient

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Rug of Smothering

Flying
Whenever a player casts a spell, they lose 1 life for each spell they've cast this turn.

Aurora of Emrakul

Flying, deathtouch
Whenever this creature attacks, each opponent loses 3 life.

Cryptolith Fragment

This artifact enters tapped.
{T}: Add one mana of any color. Each player loses 1 life.
At the beginning of your upkeep, if each player has 10 or less life, transform this artifact.

Cryptolith Fragment // Aurora of Emrakul

Arcane Signet

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

Puppet Strings

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

Commander's Sphere

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

Burning-Tree Shaman

Whenever a player activates an ability that isn't a mana ability, this creature deals 1 damage to that player.

Heartless Hidetsugu

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

Kardur, Doomscourge

When Kardur enters, until your next turn, creatures your opponents control attack each combat if able and attack a player other than you if able.
Whenever an attacking creature dies, each opponent loses 1 life and you gain 1 life.

Lavabrink Floodgates

{T}: Add {R}{R}.
At the beginning of each player's upkeep, that player may put a doom counter on this artifact or remove a doom counter from it. Then if it has three or more doom counters on it, sacrifice this artifact. When you do, it deals 6 damage to each creature.

Belbe, Corrupted Observer

At the beginning of each postcombat main phase, the active player adds {C}{C} for each of your opponents who lost life this turn. (Damage causes loss of life.)

Fireball

This spell costs {1} more to cast for each target beyond the first.
Fireball deals X damage divided evenly, rounded down, among any number of targets.

Capricopian

This creature enters with X +1/+1 counters on it.
{2}: Put a +1/+1 counter on this creature, then you may reselect which player this creature is attacking. Only the player this creature is attacking may activate this ability and only during the declare attackers step. (It can't attack its controller.)

Nightshade Harvester

Whenever a land an opponent controls enters, that player loses 1 life. Put a +1/+1 counter on this creature.

Scytheclaw Raptor

Whenever a player casts a spell, if it's not their turn, this creature deals 4 damage to them.

Coveted Jewel

When this artifact enters, draw three cards.
{T}: Add three mana of any one color.
Whenever one or more creatures an opponent controls attack you and aren't blocked, that player draws three cards and gains control of this artifact. Untap it.

Moss Diamond

This artifact enters tapped.
{T}: Add {G}.

Carnage Gladiator

Whenever a creature blocks, that creature's controller loses 1 life.
{1}{B}{R}: Regenerate this creature.

Spectral Searchlight

{T}: Choose a player. That player adds one mana of any color they choose.

Xira Arien

Flying
{B}{R}{G}, {T}: Target player draws a card.

Rite of the Raging Storm

Creatures named Lightning Rager can't attack you or planeswalkers you control.
At the beginning of each player's upkeep, that player creates a 5/1 red Elemental creature token named Lightning Rager. It has trample, haste, and "At the beginning of the end step, sacrifice this token."

Prismatic Lens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Apocalypse Hydra

This creature enters with X +1/+1 counters on it. If X is 5 or more, it enters with an additional X +1/+1 counters on it.
{1}{R}, Remove a +1/+1 counter from this creature: It deals 1 damage to any target.

Blinkmoth Urn

At the beginning of each player's first main phase, if this artifact is untapped, that player adds {C} for each artifact they control.

Fertile Ground

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Feral Hydra

This creature enters with X +1/+1 counters on it.
{3}: Put a +1/+1 counter on this creature. Any player may activate this ability.

Rosheen Meanderer

{T}: Add {C}{C}{C}{C}. Spend this mana only on costs that contain {X}.

Spore Frog

Sacrifice this creature: Prevent all combat damage that would be dealt this turn.

Rakdos Signet

Astral Cornucopia

This artifact enters with X charge counters on it.
{T}: Choose a color. Add one mana of that color for each charge counter on this artifact.

Havoc Festival

Players can't gain life.
At the beginning of each player's upkeep, that player loses half their life, rounded up.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Lightning Reaver

Haste; fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever this creature deals combat damage to a player, put a charge counter on it.
At the beginning of your end step, this creature deals damage equal to the number of charge counters on it to each opponent.

Power Surge

At the beginning of each player's upkeep, this enchantment deals X damage to that player, where X is the number of untapped lands they controlled at the beginning of this turn.

Golgari Signet

Rootweaver Druid

When this creature enters, each opponent may search their library for up to three basic land cards. They each put one of those cards onto the battlefield tapped under your control and the rest onto the battlefield tapped under their control. Then each player who searched their library this way shuffles.