Mythos of Snapdax

Each player chooses an artifact, a creature, an enchantment, and a planeswalker from among the nonland permanents they control, then sacrifices the rest. If {B}{R} was spent to cast this spell, you choose the permanents for each player instead.

Tome of Legends

This artifact enters with a page counter on it.
Whenever your commander enters or attacks, put a page counter on this artifact.
{1}, {T}, Remove a page counter from this artifact: Draw a card.

Fervent Charge

Whenever a creature you control attacks, it gets +2/+2 until end of turn.

Captain Lannery Storm

Haste
Whenever Captain Lannery Storm attacks, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Whenever you sacrifice a Treasure, Captain Lannery Storm gets +1/+0 until end of turn.

Boros Signet

Swamp

Crackling Doom

Crackling Doom deals 2 damage to each opponent. Each opponent sacrifices a creature with the greatest power among creatures that player controls.

Adriana, Captain of the Guard

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Other creatures you control have melee. (If a creature has multiple instances of melee, each triggers separately.)

Isshin, Two Heavens as One

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

Glint-Sleeve Siphoner

Menace
Whenever this creature enters or attacks, you get {E} (an energy counter).
At the beginning of your upkeep, you may pay {E}{E}. If you do, you draw a card and you lose 1 life.

Rakshasa Debaser

Whenever this creature attacks, put target creature card from defending player's graveyard onto the battlefield under your control.
Encore {6}{B}{B} ({6}{B}{B}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Fey Steed

Whenever this creature attacks, another target attacking creature you control gains indestructible until end of turn.
Whenever a creature or planeswalker you control becomes the target of a spell or ability an opponent controls, you may draw a card.

Etali, Primal Storm

Whenever Etali attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Plains

Slayers' Stronghold

{T}: Add {C}.
{R}{W}, {T}: Target creature gets +2/+0 and gains vigilance and haste until end of turn.

Terminate

Destroy target creature. It can't be regenerated.

Dire Tactics

Exile target creature. If you don't control a Human, you lose life equal to that creature's toughness.

Revenge of Ravens

Whenever a creature attacks you or a planeswalker you control, that creature's controller loses 1 life and you gain 1 life.

Leonin Warleader

Whenever this creature attacks, create two 1/1 white Cat creature tokens with lifelink that are tapped and attacking.

Ebony Fly

This artifact enters tapped.
{T}: Add {C}.
{4}: Roll a d6. Until end of turn, you may have this artifact become an X/X Insect artifact creature with flying, where X is the result.
Whenever this artifact attacks, another target attacking creature gains flying until end of turn.

Brutal Hordechief

Whenever a creature you control attacks, defending player loses 1 life and you gain 1 life.
{3}{R/W}{R/W}: Creatures your opponents control block this turn if able, and you choose how those creatures block.

Kazuul, Tyrant of the Cliffs

Whenever a creature an opponent controls attacks, if you're the defending player, create a 3/3 red Ogre creature token unless that creature's controller pays {3}.

Nomad Outpost

This land enters tapped.
{T}: Add {R}, {W}, or {B}.

Sun Titan

Vigilance
Whenever this creature enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Argentum Armor

Equipped creature gets +6/+6.
Whenever equipped creature attacks, destroy target permanent.
Equip {6}

Tainted Field

{T}: Add {C}.
{T}: Add {W} or {B}. Activate only if you control a Swamp.

Mardu Strike Leader

Whenever this creature attacks, create a 2/1 black Warrior creature token.
Dash {3}{B} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Avenging Huntbonder

Double strike
Whenever this creature attacks, put a double strike counter on another target attacking creature.

Aurelia, the Warleader

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

Marble Diamond

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

Mountain

Search the Premises

Whenever a creature attacks you or a planeswalker you control, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Evolving Wilds

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

Damn

Destroy target creature. A creature destroyed this way can't be regenerated.
Overload {2}{W}{W} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. This land deals 1 damage to you.

Archon of Cruelty

Flying
Whenever this creature enters or attacks, target opponent sacrifices a creature or planeswalker of their choice, discards a card, and loses 3 life. You draw a card and gain 3 life.

Sign in Blood

Target player draws two cards and loses 2 life.

Tainted Peak

{T}: Add {C}.
{T}: Add {B} or {R}. Activate only if you control a Swamp.

Orzhov Signet

Rogue's Passage

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

Solemn Simulacrum

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

Tear

Destroy target enchantment.
Fuse (You may cast one or both halves of this card from your hand.)

Wear

Destroy target artifact.
Fuse (You may cast one or both halves of this card from your hand.)

Wear // Tear

Rakdos Signet

Sunhome, Fortress of the Legion

{T}: Add {C}.
{2}{R}{W}, {T}: Target creature gains double strike until end of turn.

Hero of Oxid Ridge

Haste
Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)
Whenever this creature attacks, creatures with power 1 or less can't block this turn.

Heartwarming Redemption

Discard all the cards in your hand, then draw that many cards plus one. You gain life equal to the number of cards in your hand.

Drakuseth, Maw of Flames

Flying
Whenever Drakuseth attacks, it deals 4 damage to any target and 3 damage to each of up to two other targets.

Tectonic Giant

Whenever this creature attacks or becomes the target of a spell an opponent controls, choose one —
• This creature deals 3 damage to each opponent.
• Exile the top two cards of your library. Choose one of them. Until the end of your next turn, you may play that card.

Arcane Signet

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

By Force

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.)
This land 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.

Cleansing Nova

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

Mardu Ascendancy

Whenever a nontoken creature you control attacks, create a 1/1 red Goblin creature token that's tapped and attacking.
Sacrifice this enchantment: Creatures you control get +0/+3 until end of turn.

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Silverwing Squadron

Flying, vigilance
Silverwing Squadron's power and toughness are each equal to the number of creatures you control.
Whenever this creature attacks, create a number of 2/2 white Knight creature tokens with vigilance equal to the number of opponents you have.

Mob Rule

Choose one —
• Gain control of all creatures with power 4 or greater until end of turn. Untap those creatures. They gain haste until end of turn.
• Gain control of all creatures with power 3 or less until end of turn. Untap those creatures. They gain haste until end of turn.

Lightning Runner

Double strike, haste
Whenever this creature attacks, you get {E}{E} (two energy counters), then you may pay eight {E}. If you pay, untap all creatures you control, and after this phase, there is an additional combat phase.

Exotic Orchard

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

Sword of the Animist

Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {2}

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.)
This land 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.

Charcoal Diamond

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

Smoldering Marsh

({T}: Add {B} or {R}.)
This land enters tapped unless you control two or more basic lands.

Collective Defiance

Escalate {1} (Pay this cost for each mode chosen beyond the first.)
Choose one or more —
• Target player discards all the cards in their hand, then draws that many cards.
• Collective Defiance deals 4 damage to target creature.
• Collective Defiance deals 3 damage to target opponent or planeswalker.

Emberwilde Captain

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

Vicious Conquistador

Whenever this creature attacks, each opponent loses 1 life.

Caves of Koilos

{T}: Add {C}.
{T}: Add {W} or {B}. This land deals 1 damage to you.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Sungold Sentinel

Whenever this creature enters or attacks, exile up to one target card from a graveyard.
Coven — {1}{W}: Choose a color. This creature gains hexproof from that color until end of turn and can't be blocked by creatures of that color this turn. Activate only if you control three or more creatures with different powers.

Terramorphic Expanse

Duelist's Heritage

Whenever one or more creatures attack, you may have target attacking creature gain double strike until end of turn.

Fire Diamond

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

Hellrider

Haste
Whenever a creature you control attacks, this creature deals 1 damage to the player or planeswalker it's attacking.

Underworld Sentinel

Whenever this creature attacks, exile target creature card from your graveyard.
When this creature dies, put all cards exiled with it onto the battlefield.

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.

Sol Ring

Shiny Impetus

Enchant creature
Enchanted creature gets +2/+2 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
Whenever enchanted creature attacks, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

By Invitation Only

Choose a number between 0 and 13. Each player sacrifices that many creatures of their choice.

Burnished Hart

{3}, Sacrifice this creature: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Despark

Exile target permanent with mana value 4 or greater.

Karazikar, the Eye Tyrant

Whenever you attack a player, tap target creature that player controls and goad it. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)
Whenever an opponent attacks another one of your opponents, you and the attacking player each draw a card and lose 1 life.

Treasury Thrull

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever this creature attacks, you may return target artifact, creature, or enchantment card from your graveyard to your hand.