Jeska, Thrice Reborn

Jeska, Thrice Reborn enters the battlefield with a loyalty counter on her for each time you've cast a commander from the command zone this game.
0: Choose target creature. Until your next turn, if that creature would deal combat damage to one of your opponents, it deals triple that damage to that player instead.
−X: Jeska, Thrice Reborn deals X damage to each of up to three targets.
Jeska, Thrice Reborn can be your commander.
Partner

The Haunt of Hightower

Flying, lifelink
Whenever The Haunt of Hightower attacks, defending player discards a card.
Whenever a card is put into an opponent's graveyard from anywhere, put a +1/+1 counter on The Haunt of Hightower.

Furnace of Rath

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

Wound Reflection

At the beginning of each end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Leyline of Combustion

If Leyline of Combustion is in your opening hand, you may begin the game with it on the battlefield.
Whenever you and/or at least one permanent you control becomes the target of a spell or ability an opponent controls, Leyline of Combustion deals 2 damage to that player.

Bite of the Black Rose

Will of the council — Starting with you, each player votes for sickness or psychosis. If sickness gets more votes, creatures your opponents control get -2/-2 until end of turn. If psychosis gets more votes or the vote is tied, each opponent discards two cards.

Sangromancer

Flying
Whenever a creature an opponent controls dies, you may gain 3 life.
Whenever an opponent discards a card, you may gain 3 life.

Capital Punishment

Council's dilemma — Starting with you, each player votes for death or taxes. Each opponent sacrifices a creature for each death vote and discards a card for each taxes vote.

Arterial Flow

Each opponent discards two cards. If you control a Vampire, each opponent loses 2 life and you gain 2 life.

Maddening Hex

Enchant player
Whenever enchanted player casts a noncreature spell, roll a d6. Maddening Hex deals damage to that player equal to the result. Then attach Maddening Hex to another one of your opponents chosen at random.

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature.

Sanguine Bond

Whenever you gain life, target opponent loses that much life.

Cemetery Gatekeeper

First strike
When Cemetery Gatekeeper enters the battlefield, exile a card from a graveyard.
Whenever a player plays a land or casts a spell, if it shares a card type with the exiled card, Cemetery Gatekeeper deals 2 damage to that player.

Incite Rebellion

For each player, Incite Rebellion deals damage to that player and each creature that player controls equal to the number of creatures they control.

Chandra's Spitfire

Flying
Whenever an opponent is dealt noncombat damage, Chandra's Spitfire gets +3/+0 until end of turn.

Tainted Remedy

If an opponent would gain life, that player loses that much life instead.

Firebrand Archer

Whenever you cast a noncreature spell, Firebrand Archer deals 1 damage to each opponent.

Black Market

Whenever a creature dies, put a charge counter on Black Market.
At the beginning of your precombat main phase, add {B} for each charge counter on Black Market.

Kediss, Emberclaw Familiar

Whenever a commander you control deals combat damage to an opponent, it deals that much damage to each other opponent.
Partner (You can have two commanders if both have partner.)

Anger of the Gods

Anger of the Gods deals 3 damage to each creature. If a creature dealt damage this way would die this turn, exile it instead.

Gremlin Infestation

Enchant artifact
At the beginning of your end step, Gremlin Infestation deals 2 damage to enchanted artifact's controller.
When enchanted artifact is put into a graveyard, create a 2/2 red Gremlin creature token.

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Cao Cao, Lord of Wei

{T}: Target opponent discards two cards. Activate only during your turn, before attackers are declared.

Bloodchief Ascension

At the beginning of each end step, if an opponent lost 2 or more life this turn, you may put a quest counter on Bloodchief Ascension. (Damage causes loss of life.)
Whenever a card is put into an opponent's graveyard from anywhere, if Bloodchief Ascension has three or more quest counters on it, you may have that player lose 2 life. If you do, you gain 2 life.

Bonfire of the Damned

Bonfire of the Damned deals X damage to target player or planeswalker and each creature that player or that planeswalker's controller controls.
Miracle {X}{R} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Fiendish Duo

First strike
If a source would deal damage to an opponent, it deals double that damage to that player instead.

Davriel, Rogue Shadowmage

At the beginning of each opponent's upkeep, if that player has one or fewer cards in hand, Davriel, Rogue Shadowmage deals 2 damage to them.
−1: Target player discards a card.

The Raven Man

At the beginning of each end step, if a player discarded a card this turn, create a 1/1 black Bird creature token with flying and "This creature can't block."
{3}{B}, {T}: Each opponent discards a card. Activate only as a sorcery.

Manabarbs

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

Guul Draz Specter

Flying
Guul Draz Specter gets +3/+3 as long as an opponent has no cards in hand.
Whenever Guul Draz Specter deals combat damage to a player, that player discards a card.

Mogis, God of Slaughter

Indestructible
As long as your devotion to black and red is less than seven, Mogis isn't a creature.
At the beginning of each opponent's upkeep, Mogis deals 2 damage to that player unless they sacrifice a creature.

Hour of Devastation

All creatures lose indestructible until end of turn. Hour of Devastation deals 5 damage to each creature and each non-Bolas planeswalker.

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.

Dictate of Erebos

Flash
Whenever a creature you control dies, each opponent sacrifices a creature.

Syphon Mind

Each other player discards a card. You draw a card for each card discarded this way.

Goblin Goliath

When Goblin Goliath enters the battlefield, create a number of 1/1 red Goblin creature tokens equal to the number of opponents you have.
{3}{R}, {T}: If a source you control would deal damage to an opponent this turn, it deals double that damage to that player instead.

Fell Specter

Flying
When Fell Specter enters the battlefield, target opponent discards a card.
Whenever an opponent discards a card, that player loses 2 life.

Crackle with Power

Crackle with Power deals five times X damage to each of up to X targets.

Hissing Iguanar

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

Heartless Hidetsugu

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

Unnerve

Chandra's Ignition

Target creature you control deals damage equal to its power to each other creature and each opponent.

Comet Storm

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.)
Choose any target, then choose another target for each time this spell was kicked. Comet Storm deals X damage to each of them.

Archon of Cruelty

Flying
Whenever Archon of Cruelty enters the battlefield or attacks, target opponent sacrifices a creature or planeswalker, discards a card, and loses 3 life. You draw a card and gain 3 life.

Kaervek the Merciless

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

Revel in Riches

Whenever a creature an opponent controls dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
At the beginning of your upkeep, if you control ten or more Treasures, you win the game.

Angrath, the Flame-Chained

+1: Each opponent discards a card and loses 2 life.
−3: Gain control of target creature until end of turn. Untap it. It gains haste until end of turn. Sacrifice it at the beginning of the next end step if it has mana value 3 or less.
−8: Each opponent loses life equal to the number of cards in their graveyard.

Fire Servant

If a red instant or sorcery spell you control would deal damage, it deals double that damage instead.

Enchanter's Bane

At the beginning of your end step, target enchantment deals damage equal to its mana value to its controller unless that player sacrifices it.

Liliana's Specter

Flying
When Liliana's Specter enters the battlefield, each opponent discards a card.

Obsidian Fireheart

{1}{R}{R}: Put a blaze counter on target land without a blaze counter on it. For as long as that land has a blaze counter on it, it has "At the beginning of your upkeep, this land deals 1 damage to you." (The land continues to burn after Obsidian Fireheart has left the battlefield.)

Pain Magnification

Whenever an opponent is dealt 3 or more damage by a single source, that player discards a card.

Hypnotic Specter

Flying
Whenever Hypnotic Specter deals damage to an opponent, that player discards a card at random.

Deathbringer Thoctar

Whenever another creature dies, you may put a +1/+1 counter on Deathbringer Thoctar.
Remove a +1/+1 counter from Deathbringer Thoctar: It deals 1 damage to any target.

Quest for the Nihil Stone

Whenever an opponent discards a card, you may put a quest counter on Quest for the Nihil Stone.
At the beginning of each opponent's upkeep, if that player has no cards in hand and Quest for the Nihil Stone has two or more quest counters on it, you may have that player lose 5 life.

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.

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.

Fate Unraveler

Whenever an opponent draws a card, Fate Unraveler deals 1 damage to that player.

Elderfang Disciple

When Elderfang Disciple enters the battlefield, each opponent discards a card.

Liliana, Waker of the Dead

+1: Each player discards a card. Each opponent who can't loses 3 life.
−3: Target creature gets -X/-X until end of turn, where X is the number of cards in your graveyard.
−7: You get an emblem with "At the beginning of combat on your turn, put target creature card from a graveyard onto the battlefield under your control. It gains haste."

Remorseless Punishment

Target opponent loses 5 life unless that player discards two cards or sacrifices a creature or planeswalker. Repeat this process once.

Mizzium Mortars

Mizzium Mortars deals 4 damage to target creature you don't control.
Overload {3}{R}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Underworld Dreams

Whenever an opponent draws a card, Underworld Dreams deals 1 damage to that player.

Magmatic Force

At the beginning of each upkeep, Magmatic Force deals 3 damage to any target.

Fiery Emancipation

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

Court of Ambition

When Court of Ambition enters the battlefield, you become the monarch.
At the beginning of your upkeep, each opponent loses 3 life unless they discard a card. If you're the monarch, instead each opponent loses 6 life unless they discard two cards.

Raiders' Wake

Whenever an opponent discards a card, that player loses 2 life.
Raid — At the beginning of your end step, if you attacked this turn, target opponent discards a card.

Black Market Connections

At the beginning of your precombat main phase, choose one or more —
• Sell Contraband — Create a Treasure token. You lose 1 life.
• Buy Information — Draw a card. You lose 2 life.
• Hire a Mercenary — Create a 3/2 colorless Shapeshifter creature token with changeling. You lose 3 life. (It has every creature type.)

Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

Leyline of Punishment

If Leyline of Punishment is in your opening hand, you may begin the game with it on the battlefield.
Players can't gain life.
Damage can't be prevented.

Tergrid's Lantern

{T}: Target player loses 3 life unless they sacrifice a nonland permanent or discard a card.
{3}{B}: Untap Tergrid's Lantern.

Tergrid, God of Fright

Menace
Whenever an opponent sacrifices a nontoken permanent or discards a permanent card, you may put that card from a graveyard onto the battlefield under your control.