Eel Umbra

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature gets +1/+1.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Mystic Monastery

Mystic Monastery enters tapped.
{T}: Add {U}, {R}, or {W}.

Talisman of Creativity

{T}: Add {C}.
{T}: Add {U} or {R}. Talisman of Creativity deals 1 damage to you.

Arcane Signet

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

Psychotic Fury

Target multicolored creature gains double strike until end of turn.
Draw a card.

Reliquary Tower

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

Izzet Signet

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

Whirlwind of Thought

Whenever you cast a noncreature spell, draw a card.

Mother of Runes

{T}: Target creature you control gains protection from the color of your choice until end of turn.

Blacksmith's Skill

Target permanent gains hexproof and indestructible until end of turn. If it's an artifact creature, it gets +2/+2 until end of turn.

Fireshrieker

Equipped creature has double strike. (It deals both first-strike and regular combat damage.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Boros Garrison

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

Curiosity

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Jeska, Thrice Reborn

Jeska, Thrice Reborn enters 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

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.

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}

Command Tower

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.

Azorius Chancery

Azorius Chancery enters tapped.
When Azorius Chancery enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

All That Glitters

Enchant creature
Enchanted creature gets +1/+1 for each artifact and/or enchantment you control.

Boros Signet

Sea of Clouds

Sea of Clouds enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Terramorphic Expanse

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

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

Azorius Signet

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

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.

Negate

Duelist's Heritage

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

Slayers' Stronghold

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

Lightning Greaves

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

Esior, Wardwing Familiar

Flying
Spells your opponents cast that target one or more commanders you control cost {3} more to cast.
Partner (You can have two commanders if both have partner.)

Plains

Silent Arbiter

No more than one creature can attack each combat.
No more than one creature can block each combat.

Slip Out the Back

Put a +1/+1 counter on target creature. It phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

Armored Skyhunter

Flying
Whenever Armored Skyhunter attacks, look at the top six cards of your library. You may put an Aura or Equipment card from among them onto the battlefield. If an Equipment is put onto the battlefield this way, you may attach it to a creature you control. Put the rest of those cards on the bottom of your library in a random order.

Mountain

March of Swirling Mist

As an additional cost to cast this spell, you may exile any number of blue cards from your hand. This spell costs {2} less to cast for each card exiled this way.
Up to X target creatures phase out. (While they're phased out, they're treated as though they don't exist. Each one phases in before its controller untaps during their next untap step.)

Mask of Memory

Whenever equipped creature deals combat damage to a player, you may draw two cards. If you do, discard a card.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Island

Talisman of Conviction

{T}: Add {C}.
{T}: Add {R} or {W}. Talisman of Conviction deals 1 damage to you.

Open the Armory

Search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.

Unleash Fury

Double the power of target creature until end of turn.

Sol Ring

Sram, Senior Edificer

Whenever you cast an Aura, Equipment, or Vehicle spell, draw a card.

Steel of the Godhead

Enchant creature
As long as enchanted creature is white, it gets +1/+1 and has lifelink. (Damage dealt by the creature also causes its controller to gain that much life.)
As long as enchanted creature is blue, it gets +1/+1 and can't be blocked.

Exotic Orchard

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

Training Center

Training Center enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Inquisitor's Flail

If equipped creature would deal combat damage, it deals double that damage instead.
If another creature would deal combat damage to equipped creature, it deals double that damage to equipped creature instead.
Equip {2}

Lizard Blades

Double strike
Equipped creature has double strike.
Reconfigure {2} ({2}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Ishai, Ojutai Dragonspeaker

Flying
Whenever an opponent casts a spell, put a +1/+1 counter on Ishai, Ojutai Dragonspeaker.
Partner (You can have two commanders if both have partner.)

Blasphemous Act

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

Divine Reckoning

Each player chooses a creature they control. Destroy the rest.
Flashback {5}{W}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.)

Slash the Ranks

Destroy all creatures and planeswalkers except for commanders.

Hindering Light

Counter target spell that targets you or a permanent you control.
Draw a card.

Flaming Fist

Commander creatures you own have "Whenever this creature attacks, it gains double strike until end of turn."

Reyav, Master Smith

Whenever a creature you control that's enchanted or equipped attacks, that creature gains double strike until end of turn.

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Siren Stormtamer

Flying
{U}, Sacrifice Siren Stormtamer: Counter target spell or ability that targets you or a creature you control.

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.

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters, you may pay 2 life. If you don't, it enters tapped.

Sunhome, Fortress of the Legion

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

Angelfire Ignition

Put two +1/+1 counters on target creature. It gains vigilance, trample, lifelink, indestructible, and haste until end of turn.
Flashback {2}{R}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Gods Willing

Target creature you control gains protection from the color of your choice until end of turn. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything of that color.)
Scry 1.

Darksteel Mutation

Enchant creature
Enchanted creature is an Insect artifact creature with base power and toughness 0/1 and has indestructible, and it loses all other abilities, card types, and creature types.

Rogue's Passage

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

Selfless Savior

Sacrifice Selfless Savior: Another target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Bastion Protector

Commander creatures you control get +2/+2 and have indestructible.

Hyena Umbra

Enchant creature
Enchanted creature gets +1/+1 and has first strike.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Staggering Insight

Enchant creature
Enchanted creature gets +1/+1 and has lifelink and "Whenever this creature deals combat damage to a player, draw a card."

Loxodon Warhammer

Equipped creature gets +3/+0 and has trample and lifelink.
Equip {3}

Ardenn, Intrepid Archaeologist

At the beginning of combat on your turn, you may attach any number of Auras and Equipment you control to target permanent or player.
Partner (You can have two commanders if both have partner.)

Axgard Armory

Axgard Armory enters tapped.
{T}: Add {W}.
{1}{R}{R}{W}, {T}, Sacrifice Axgard Armory: Search your library for an Aura card and/or an Equipment card, reveal them, put them into your hand, then shuffle.

Spectator Seating

Spectator Seating enters tapped unless you have two or more opponents.
{T}: Add {R} or {W}.

Aqueous Form

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Combat Research

Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, draw a card."
As long as enchanted creature is legendary, it gets +1/+1 and has ward {1}. (Whenever enchanted creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

Akiri, Fearless Voyager

Whenever you attack a player with one or more equipped creatures, draw a card.
{W}: You may unattach an Equipment from a creature you control. If you do, tap that creature and it gains indestructible until end of turn.

Seize the Day

Untap target creature. After this main phase, there is an additional combat phase followed by an additional main phase.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Evolving Wilds

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

Spirit Mantle

Enchant creature
Enchanted creature gets +1/+1 and has protection from creatures.

Swords to Plowshares

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

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.