Vicious Shadows

Whenever a creature dies, you may have Vicious Shadows deal damage to target player equal to the number of cards in that player's hand.

Runeflare Trap

If an opponent drew three or more cards this turn, you may pay {R} rather than pay this spell's mana cost.
Runeflare Trap deals damage to target player equal to the number of cards in that player's hand.

Heartless Hidetsugu

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

Treasure

{T}, Sacrifice this artifact: Add one mana of any color.

Venser's Journal

You have no maximum hand size.
At the beginning of your upkeep, you gain 1 life for each card in your hand.

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.)

Empyrial Plate

Equipped creature gets +1/+1 for each card in your hand.
Equip {2}

Anger

Haste
As long as Anger is in your graveyard and you control a Mountain, creatures you control have haste.

Shunt

Change the target of target spell with a single target.

Otherworld Atlas

{T}: Put a charge counter on Otherworld Atlas.
{T}: Each player draws a card for each charge counter on Otherworld Atlas.

Adamaro, First to Desire

Adamaro, First to Desire's power and toughness are each equal to the number of cards in the hand of the opponent with the most cards in hand.

Temple Bell

Reverberate

Copy target instant or sorcery spell. You may choose new targets for the copy.

Spiraling Embers

Spiraling Embers deals damage to any target equal to the number of cards in your hand.

Dualcaster Mage

Flash
When Dualcaster Mage enters the battlefield, copy target instant or sorcery spell. You may choose new targets for the copy.

Viashino Heretic

{1}{R}, {T}: Destroy target artifact. Viashino Heretic deals damage to that artifact's controller equal to the artifact's mana value.

Sweeping Cleave

Target creature you control gains double strike until end of turn. (Then exile this card. You may cast the artifact later from exile.)

Two-Handed Axe

Whenever equipped creature attacks, double its power until end of turn.
Equip {1}{R}

Two-Handed Axe // Sweeping Cleave

Howling Golem

Whenever Howling Golem attacks or blocks, each player draws a card.

Iron Maiden

At the beginning of each opponent's upkeep, Iron Maiden deals X damage to that player, where X is the number of cards in their hand minus 4.

Zenith Chronicler

Whenever a player casts their first multicolored spell each turn, each other player draws a card.

Coveted Jewel

When Coveted Jewel enters the battlefield, 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 Coveted Jewel. Untap it.

Sulfuric Vortex

At the beginning of each player's upkeep, Sulfuric Vortex deals 2 damage to that player.
If a player would gain life, that player gains no life instead.

Humble Defector

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

Stormbreath Dragon

Flying, haste, protection from white
{5}{R}{R}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
When Stormbreath Dragon becomes monstrous, it deals damage to each opponent equal to the number of cards in that player's hand.

Gamble

Search your library for a card, put that card into your hand, discard a card at random, then shuffle.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Mikokoro, Center of the Sea

{T}: Add {C}.
{2}, {T}: Each player draws a card.

Goblin Engineer

When Goblin Engineer enters the battlefield, you may search your library for an artifact card, put it into your graveyard, then shuffle.
{R}, {T}, Sacrifice an artifact: Return target artifact card with mana value 3 or less from your graveyard to the battlefield.

Sudden Impact

Sudden Impact deals damage to target player equal to the number of cards in that player's hand.

Ebony Owl Netsuke

At the beginning of each opponent's upkeep, if that player has seven or more cards in hand, Ebony Owl Netsuke deals 4 damage to that player.

Valakut, the Molten Pinnacle

Valakut, the Molten Pinnacle enters the battlefield tapped.
Whenever a Mountain enters the battlefield under your control, if you control at least five other Mountains, you may have Valakut, the Molten Pinnacle deal 3 damage to any target.
{T}: Add {R}.

Skullcage

At the beginning of each opponent's upkeep, Skullcage deals 2 damage to that player unless they have exactly three or exactly four cards in hand.

Blood Moon

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

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, Pain Distributor deals 1 damage to that player.

Wheel of Fate

Suspend 4—{1}{R} (Rather than cast this card from your hand, pay {1}{R} and exile it with four time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
Each player discards their hand, then draws seven cards.

Arcane Signet

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

Mountain

Shah of Naar Isle

Trample
Echo {0} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Shah of Naar Isle's echo cost is paid, each opponent may draw up to three cards.

Price of Progress

Price of Progress deals damage to each player equal to twice the number of nonbasic lands that player controls.

Reforge the Soul

Each player discards their hand, then draws seven cards.
Miracle {1}{R} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Howling Mine

At the beginning of each player's draw step, if Howling Mine is untapped, that player draws an additional card.

Acolyte Hybrid

Heavy Rock Cutter — Whenever Acolyte Hybrid attacks, destroy up to one target artifact. If an artifact is destroyed this way, its controller draws a card.

Fateful Showdown

Fateful Showdown deals damage to any target equal to the number of cards in your hand. Discard all the cards in your hand, then draw that many cards.

Horn of Plenty

Whenever a player casts a spell, they may pay {1}. If the player does, they draw a card at the beginning of the next end step.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Molten Psyche

Each player shuffles the cards from their hand into their library, then draws that many cards.
Metalcraft — If you control three or more artifacts, Molten Psyche deals damage to each opponent equal to the number of cards that player has drawn this turn.

Sol Ring

Black Vise

As Black Vise enters the battlefield, choose an opponent.
At the beginning of the chosen player's upkeep, Black Vise deals X damage to that player, where X is the number of cards in their hand minus 4.

Khorvath's Fury

For each player, choose friend or foe. Each friend discards all cards from their hand, then draws that many cards plus one. Khorvath's Fury deals damage to each foe equal to the number of cards in their hand.

Solemn Simulacrum

When Solemn Simulacrum enters the battlefield, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Soldevi Sentry

{1}: Choose target opponent. Regenerate Soldevi Sentry. When it regenerates this way, that player may draw a card.

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.")

Bloodsworn Steward

Flying
Commander creatures you control get +2/+2 and have haste.

Temur Battle Rage

Target creature gains double strike until end of turn.
Ferocious — That creature also gains trample until end of turn if you control a creature with power 4 or greater.

Horn of Greed

Whenever a player plays a land, that player draws a card.

Mindclaw Shaman

When Mindclaw Shaman enters the battlefield, target opponent reveals their hand. You may cast an instant or sorcery spell from among those cards without paying its mana cost.

Unquenchable Fury

Enchant creature
Enchanted creature has "Whenever this creature attacks, it deals X damage to defending player, where X is the number of cards in their hand."
When Unquenchable Fury is put into your graveyard from the battlefield, return it to your hand.

Emberwilde Captain

When Emberwilde Captain enters the battlefield, you become the monarch.
Whenever an opponent attacks you while you're the monarch, Emberwilde Captain deals damage to that player equal to the number of cards in their hand.

Gaze of Adamaro

Gaze of Adamaro deals damage to target player equal to the number of cards in that player's hand.

Ruby Medallion

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

Misers' Cage

At the beginning of each opponent's upkeep, if that player has five or more cards in hand, Misers' Cage deals 2 damage to that player.

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.)

Guff Rewrites History

For each player, choose target nonenchantment, nonland permanent that player controls. Those permanents' owners shuffle them into their libraries. Each player who controlled one of those permanents exiles cards from the top of their library until they exile a nonland card, then puts the rest on the bottom of their library in a random order. Each player may cast the nonland card they exiled without paying its mana cost.