Arni Metalbrow

Whenever a creature you control attacks or a creature you control enters attacking, you may pay {1}{R}. If you do, you may put a creature card with mana value less than that creature's mana value from your hand onto the battlefield tapped and attacking.

Elturel Survivors

Trample, myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
As long as Elturel Survivors is attacking, it gets +X/+0, where X is the number of lands defending player controls.

Goblin Bombardment

Sacrifice a creature: Goblin Bombardment deals 1 damage to any target.

Strionic Resonator

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

Caves of Chaos Adventurer

Trample
When Caves of Chaos Adventurer enters, you take the initiative.
Whenever Caves of Chaos Adventurer attacks, exile the top card of your library. If you've completed a dungeon, you may play that card this turn without paying its mana cost. Otherwise, you may play that card this turn.

Furycalm Snarl

As Furycalm Snarl enters, you may reveal a Mountain or Plains card from your hand. If you don't, Furycalm Snarl enters tapped.
{T}: Add {R} or {W}.

Port Razer

Whenever Port Razer deals combat damage to a player, untap each creature you control. After this phase, there is an additional combat phase.
Port Razer can't attack a player it has already attacked this turn.

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Solemn Simulacrum

When Solemn Simulacrum enters, 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.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Your Temple Is Under Attack

Choose one —
• Pray for Protection — Creatures you control gain indestructible until end of turn.
• Strike a Deal — You and target opponent each draw two cards.

Have

Herald of the Host

Flying, vigilance
Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Plundering Barbarian

When Plundering Barbarian enters, choose one —
• Smash the Chest — Destroy target artifact.
• Pry It Open — Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Windbrisk Heights

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Windbrisk Heights enters tapped.
{T}: Add {W}.
{W}, {T}: You may play the exiled card without paying its mana cost if you attacked with three or more creatures this turn.

Witty Roastmaster

Alliance — Whenever another creature you control enters, Witty Roastmaster deals 1 damage to each opponent.

Austere Command

Choose two —
• Destroy all artifacts.
• Destroy all enchantments.
• Destroy all creatures with mana value 3 or less.
• Destroy all creatures with mana value 4 or greater.

Duergar Hedge-Mage

When Duergar Hedge-Mage enters, if you control two or more Mountains, you may destroy target artifact.
When Duergar Hedge-Mage enters, if you control two or more Plains, you may destroy target enchantment.

Combustible Gearhulk

First strike
When Combustible Gearhulk enters, target opponent may have you draw three cards. If the player doesn't, you mill three cards, then Combustible Gearhulk deals damage to that player equal to the total mana value of those cards.

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.

Impact Tremors

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

Knight of the White Orchid

First strike
When Knight of the White Orchid enters, if an opponent controls more lands than you, you may search your library for a Plains card, put it onto the battlefield, then shuffle.

Fanatical Devotion

Sacrifice a creature: Regenerate target creature.

Inspiring Overseer

Flying
When Inspiring Overseer enters, you gain 1 life and draw a card.

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Circuit Mender

When Circuit Mender enters, you gain 2 life.
When Circuit Mender leaves the battlefield, draw a card.

Legion Loyalty

Creatures you control have myriad. (Whenever a creature with myriad attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Hexplate Wallbreaker

For Mirrodin! (When this Equipment enters, create a 2/2 red Rebel creature token, then attach this to it.)
Equipped creature gets +2/+2.
Whenever equipped creature attacks, if it's the first combat phase of the turn, untap each attacking creature. After this phase, there is an additional combat phase.
Equip {3}{R}

Loyal Warhound

Vigilance
When Loyal Warhound enters, if an opponent controls more lands than you, search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.

Plains

Blade of Selves

Equipped creature has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Equip {4}

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Gamble

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

Crush Contraband

Choose one or both —
• Exile target artifact.
• Exile target enchantment.

Vandalblast

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

Mindclaw Shaman

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

Inferno Titan

{R}: Inferno Titan gets +1/+0 until end of turn.
Whenever Inferno Titan enters or attacks, it deals 3 damage divided as you choose among one, two, or three targets.

Bloodthirster

Flying, trample
Whenever Bloodthirster deals combat damage to a player, untap it. After this phase, there is an additional combat phase.
Bloodthirster can't attack a player it has already attacked this turn.

Hammers of Moradin

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Whenever Hammers of Moradin attacks, for each opponent, tap up to one target creature that player controls.

Duke Ulder Ravengard

At the beginning of combat on your turn, another target creature you control gains haste and myriad until end of turn. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Rogue's Passage

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

Boon-Bringer Valkyrie

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following abilities until end of turn.)
Flying, first strike, lifelink

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Sol Ring

Meteor Golem

When Meteor Golem enters, destroy target nonland permanent an opponent controls.

Arcane Signet

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

Agrus Kos, Eternal Soldier

Vigilance
Whenever Agrus Kos, Eternal Soldier becomes the target of an ability that targets only it, you may pay {1}{R/W}. If you do, copy that ability for each other creature you control that ability could target. Each copy targets a different one of those creatures. ({R/W} can be paid with either {R} or {W}.)

Aurelia, the Warleader

Flying, vigilance, haste
Whenever Aurelia, the Warleader attacks for the first time each turn, untap all creatures you control. After this phase, there is an additional combat phase.

Relentless Assault

Untap all creatures that attacked this turn. After this main phase, there is an additional combat phase followed by an additional main phase.

Temple of Triumph

Temple of Triumph enters tapped.
When Temple of Triumph enters, scry 1.
{T}: Add {R} or {W}.

Kor Cartographer

When Kor Cartographer enters, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle.

Éomer, Marshal of Rohan

Haste
Whenever one or more other attacking legendary creatures you control die, untap all creatures you control. After this phase, there is an additional combat phase. This ability triggers only once each turn.

Command Tower

Cleansing Nova

Choose one —
• Destroy all creatures.
• Destroy all artifacts and enchantments.

Mirror Box

The "legend rule" doesn't apply to permanents you control.
Each legendary creature you control gets +1/+1.
Each nontoken creature you control gets +1/+1 for each other creature you control with the same name as that creature.

Karmic Guide

Flying, protection from black
Echo {3}{W}{W} (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 Karmic Guide enters, return target creature card from your graveyard to the battlefield.

Taunt from the Rampart

Goad all creatures your opponents control. Until your next turn, those creatures can't block. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Myr Battlesphere

When Myr Battlesphere enters, create four 1/1 colorless Myr artifact creature tokens.
Whenever Myr Battlesphere attacks, you may tap X untapped Myr you control. If you do, Myr Battlesphere gets +X/+0 until end of turn and deals X damage to the player or planeswalker it's attacking.

Wind-Scarred Crag

Wind-Scarred Crag enters tapped.
When Wind-Scarred Crag enters, you gain 1 life.
{T}: Add {R} or {W}.

Boros Garrison

Boros Garrison enters tapped.
When Boros Garrison enters, return a land you control to its owner's hand.
{T}: Add {R}{W}.

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

Ascend from Avernus

Return all creature and planeswalker cards with mana value X or less from your graveyard to the battlefield. Exile Ascend from Avernus.

Éowyn, Fearless Knight

Haste
When Éowyn, Fearless Knight enters, exile target creature an opponent controls with greater power. Legendary creatures you control gain protection from each of that creature's colors until end of turn.

Priest of Ancient Lore

When Priest of Ancient Lore enters, you gain 1 life and draw a card.

Spinerock Knoll

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Spinerock Knoll enters tapped.
{T}: Add {R}.
{R}, {T}: You may play the exiled card without paying its mana cost if an opponent was dealt 7 or more damage this turn.

Neyali, Suns' Vanguard

Attacking tokens you control have double strike.
Whenever one or more tokens you control attack a player, exile the top card of your library. During any turn you attacked with a token, you may play that card.

Thought Vessel

Firbolg Flutist

Enthralling Performance — When Firbolg Flutist enters, gain control of target creature you don't control until end of turn. Untap it. It gains haste and myriad until end of turn. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Angelic Skirmisher

Flying
At the beginning of each combat, choose first strike, vigilance, or lifelink. Creatures you control gain that ability until end of turn.

Mountain

Patron of the Arts

When Patron of the Arts enters or dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Flameshadow Conjuring

Whenever a nontoken creature you control enters, you may pay {R}. If you do, create a token that's a copy of that creature. That token gains haste. Exile it at the beginning of the next end step.