Arena of Glory

This land enters tapped unless you control a Mountain.
{T}: Add {R}.
{R}, {T}, Exert this land: Add {R}{R}. If that mana is spent on a creature spell, it gains haste until end of turn. (An exerted permanent won't untap during your next untap step.)

Ryusei, the Falling Star

Flying
When Ryusei dies, it deals 5 damage to each creature without flying.

Cathodion

Duplicant

Imprint — When this creature enters, you may exile target nontoken creature.
As long as a card exiled with this creature is a creature card, this creature has the power, toughness, and creature types of the last creature card exiled with it. It's still a Shapeshifter.

Ganax, Astral Hunter

Flying
Whenever Ganax or another Dragon you control enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Choose a Background (You can have a Background as a second commander.)

Blast-Furnace Hellkite

Artifact offering (You may cast this spell as though it had flash by sacrificing an artifact and paying the difference in mana costs between this and the sacrificed artifact. Mana cost includes color.)
Flying, double strike
Creatures attacking your opponents have double strike.

Stalking Vengeance

Haste
Whenever another creature you control dies, it deals damage equal to its power to target player or planeswalker.

Electroduplicate

Create a token that's a copy of target creature you control, except it has haste and "At the beginning of the end step, sacrifice this token."
Flashback {2}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Zealous Conscripts

Haste
When this creature enters, gain control of target permanent until end of turn. Untap that permanent. It gains haste until end of turn.

Breaching Dragonstorm

When this enchantment enters, exile cards from the top of your library until you exile a nonland card. You may cast it without paying its mana cost if that spell's mana value is 8 or less. If you don't, put that card into your hand.
When a Dragon you control enters, return this enchantment to its owner's hand.

Glimpse the Impossible

Exile the top three cards of your library. You may play those cards this turn. At the beginning of the next end step, if any of those cards remain exiled, put them into your graveyard, then create a 0/1 colorless Eldrazi Spawn creature token for each card put into your graveyard this way. Those tokens have "Sacrifice this token: Add {C}."

Steel Hellkite

Flying
{2}: This creature gets +1/+0 until end of turn.
{X}: Destroy each nonland permanent with mana value X whose controller was dealt combat damage by this creature this turn. Activate only once each turn.

Basilisk Collar

Equipped creature has deathtouch and lifelink. (Any amount of damage it deals to a creature is enough to destroy it. Damage dealt by this creature also causes you to gain that much life.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Magmatic Hellkite

Flying
When this creature enters, destroy target nonbasic land an opponent controls. Its controller searches their library for a basic land card, puts it onto the battlefield tapped with a stun counter on it, then shuffles. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Junk Diver

Flying
When this creature dies, return another target artifact card from your graveyard to your hand.

Vanquisher's Banner

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

Atsushi, the Blazing Sky

Flying, trample
When Atsushi dies, choose one —
• Exile the top two cards of your library. Until the end of your next turn, you may play those cards.
• Create three Treasure tokens.

Maelstrom of the Spirit Dragon

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a Dragon spell or an Omen spell.
{4}, {T}, Sacrifice this land: Search your library for a Dragon card, reveal it, put it into your hand, then shuffle.

Priest of Urabrask

When this creature enters, add {R}{R}{R}.

Artisan of Kozilek

When you cast this spell, you may return target creature card from your graveyard to the battlefield.
Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents of their choice.)

Herigast, Erupting Nullkite

Emerge {6}{R}{R} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, you may exile your hand. If you do, draw three cards.
Flying
Each creature spell you cast has emerge. The emerge cost is equal to its mana cost.

Tecutlan, the Searing Rift

(Transforms from Brass's Tunnel-Grinder.)
{T}: Add {R}.
Whenever you cast a permanent spell using mana produced by Tecutlan, discover X, where X is that spell's mana value.

Brass's Tunnel-Grinder

When Brass's Tunnel-Grinder enters, discard any number of cards, then draw that many cards plus one.
At the beginning of your end step, if you descended this turn, put a bore counter on Brass's Tunnel-Grinder. Then if there are three or more bore counters on it, remove those counters and transform it. (You descended if a permanent card was put into your graveyard from anywhere.)

Brass's Tunnel-Grinder // Tecutlan, the Searing Rift

Dragon Mage

Flying
Whenever this creature deals combat damage to a player, each player discards their hand, then draws seven cards.

Nogi, Draco-Zealot

Dragon spells you cast cost {1} less to cast.
Whenever Nogi attacks, if you control three or more Dragons, until end of turn, Nogi becomes a Dragon with base power and toughness 5/5 and gains flying.

Patron of the Arts

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

Twinflame Tyrant

Flying
If a source you control would deal damage to an opponent or a permanent an opponent controls, it deals double that damage instead.

Enduring Courage

Whenever another creature you control enters, it gets +2/+0 and gains haste until end of turn.
When Enduring Courage dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)

Sunset Strikemaster

{T}: Add {R}.
{2}{R}, {T}, Sacrifice this creature: It deals 6 damage to target creature with flying.

Combustible Gearhulk

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

Anzrag's Rampage

Destroy all artifacts you don't control, then exile the top X cards of your library, where X is the number of artifacts that were put into graveyards from the battlefield this turn. You may put a creature card exiled this way onto the battlefield. It gains haste. Return it to your hand at the beginning of the next end step.

Skittering Precursor

Devoid (This card has no color.)
Menace
Whenever you sacrifice a nontoken permanent, create a 0/1 colorless Eldrazi Spawn creature token with "Sacrifice this token: Add {C}."

Anger

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

Knollspine Dragon

Flying
When this creature enters, you may discard your hand and draw cards equal to the damage dealt to target opponent this turn.

Thunder Dragon

Flying
When this creature enters, it deals 3 damage to each creature without flying.

Rekindling Phoenix

Flying
When this creature dies, create a 0/1 red Elemental creature token with "At the beginning of your upkeep, sacrifice this token and return target card named Rekindling Phoenix from your graveyard to the battlefield. It gains haste until end of turn."

Spawn-Gang Commander

Devoid (This card has no color.)
When you cast this spell, create three 0/1 colorless Eldrazi Spawn creature tokens with "Sacrifice this token: Add {C}."
{1}{C}, Sacrifice an Eldrazi: This creature deals 2 damage to any target.

Hideous Taskmaster

Devoid (This card has no color.)
When you cast this spell, for each opponent, gain control of up to one target creature that player controls until end of turn. Untap those creatures. They gain trample, haste, and annihilator 1 until end of turn.
Trample, haste, annihilator 1 (Whenever this creature attacks, defending player sacrifices a permanent of their choice.)

Dragonstorm Globe

Each Dragon you control enters with an additional +1/+1 counter on it.
{T}: Add one mana of any color.

Arcane Signet

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

Arid Archway

This land enters tapped.
When this land enters, return a land you control to its owner's hand. If another Desert was returned this way, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Add {C}{C}.

Thundermane Dragon

Flying
You may look at the top card of your library any time.
You may cast creature spells with power 4 or greater from the top of your library. If you cast a creature spell this way, it gains haste until end of turn.

Scourge of the Throne

Flying
Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)
Whenever this creature attacks for the first time each turn, if it's attacking the player with the most life or tied for most life, untap all attacking creatures. After this phase, there is an additional combat phase.

Blood Moon

Mountain

Hazoret's Monument

Red creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, you may discard a card. If you do, draw a card.

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.

Cursed Mirror

{T}: Add {R}.
As this artifact enters, you may have it become a copy of any creature on the battlefield until end of turn, except it has haste.

Null Elemental Blast

Choose one —
• Counter target multicolored spell.
• Destroy target multicolored permanent.

Terror of Mount Velus

Flying
Double strike (This creature deals both first-strike and regular combat damage.)
When this creature enters, creatures you control gain double strike until end of turn.

Hoarding Dragon

Flying
When this creature enters, you may search your library for an artifact card, exile it, then shuffle.
When this creature dies, you may put the exiled card into its owner's hand.

Skitterbeam Battalion

Prototype {3}{R}{R} — 2/2 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
Trample, haste
When this creature enters, if you cast it, create two tokens that are copies of it.

Dragon Tempest

Whenever a creature you control with flying enters, it gains haste until end of turn.
Whenever a Dragon you control enters, it deals X damage to any target, where X is the number of Dragons you control.

Oxidda Golem

Affinity for Mountains (This spell costs {1} less to cast for each Mountain you control.)
Haste

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Snow-Covered Wastes

Demanding Dragon

Flying
When this creature enters, it deals 5 damage to target opponent unless that player sacrifices a creature of their choice.

Sol Ring

Palladium Myr

Clone Shell

Imprint — When this creature enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom of your library in any order.
When this creature dies, turn the exiled card face up. If it's a creature card, put it onto the battlefield under your control.

Imposing Grandeur

Each player may discard their hand and draw cards equal to the greatest mana value of a commander they own on the battlefield or in the command zone.

Dragonlord's Servant

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

Gilded Lotus

Su-Chi Cave Guard

Vigilance
Ward {4} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)
When this creature dies, add eight {C}. Until end of turn, you don't lose this mana as steps and phases end.

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.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Blasphemous Act

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

Earthquake

Earthquake deals X damage to each creature without flying and each player.

Lathliss, Dragon Queen

Flying
Whenever another nontoken Dragon you control enters, create a 5/5 red Dragon creature token with flying.
{1}{R}: Dragons you control get +1/+0 until end of turn.

Wrangle

Gain control of target creature with power 4 or less until end of turn. Untap that creature. It gains haste until end of turn.