Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

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.

Gateway Plaza

Gateway Plaza enters the battlefield tapped.
When Gateway Plaza enters the battlefield, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

Trinket Mage

When Trinket Mage enters the battlefield, you may search your library for an artifact card with mana value 1 or less, reveal that card, put it into your hand, then shuffle.

One-Eyed Scarecrow

Defender
Creatures with flying your opponents control get -1/-0.

Treasure Chest

{4}, Sacrifice Treasure Chest: Roll a d20.
1 | Trapped! — You lose 3 life.
2—9 | Create five Treasure tokens.
10—19 | You gain 3 life and draw three cards.
20 | Search your library for a card. If it's an artifact card, you may put it onto the battlefield. Otherwise, put that card into your hand. Then shuffle.

Rakdos Guildgate

Rakdos Guildgate enters the battlefield tapped.
{T}: Add {B} or {R}.

Field of Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice Field of Ruin: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.

Haunted Ridge

Haunted Ridge enters the battlefield tapped unless you control two or more other lands.
{T}: Add {B} or {R}.

Molten Nursery

Devoid (This card has no color.)
Whenever you cast a colorless spell, Molten Nursery deals 1 damage to any target.

Tezzeret the Schemer

+1: Create a colorless artifact token named Etherium Cell with "{T}, Sacrifice this artifact: Add one mana of any color."
−2: Target creature gets +X/-X until end of turn, where X is the number of artifacts you control.
−7: You get an emblem with "At the beginning of combat on your turn, target artifact you control becomes an artifact creature with base power and toughness 5/5."

Door to Nothingness

Door to Nothingness enters the battlefield tapped.
{W}{W}{U}{U}{B}{B}{R}{R}{G}{G}, {T}, Sacrifice Door to Nothingness: Target player loses the game.

Realmwalker

Changeling (This card is every creature type.)
As Realmwalker enters the battlefield, choose a creature type.
You may look at the top card of your library any time.
You may cast creature spells of the chosen type from the top of your library.

Tezzeret, Artifice Master

+1: Create a 1/1 colorless Thopter artifact creature token with flying.
0: Draw a card. If you control three or more artifacts, draw two cards instead.
−9: You get an emblem with "At the beginning of your end step, search your library for a permanent card, put it onto the battlefield, then shuffle."

Universal Automaton

Changeling (This card is every creature type.)

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Azorius Guildgate

Azorius Guildgate enters the battlefield tapped.
{T}: Add {W} or {U}.

Reaper King

({2/W} can be paid with any two mana or with {W}. This card's mana value is 10.)
Other Scarecrow creatures you control get +1/+1.
Whenever another Scarecrow enters the battlefield under your control, destroy target permanent.

Scaretiller

Whenever Scaretiller becomes tapped, choose one —
• You may put a land card from your hand onto the battlefield tapped.
• Return target land card from your graveyard to the battlefield tapped.

Dimir Guildgate

Dimir Guildgate enters the battlefield tapped.
{T}: Add {U} or {B}.

Crop Rotation

As an additional cost to cast this spell, sacrifice a land.
Search your library for a land card, put that card onto the battlefield, then shuffle.

Whir of Invention

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.

Necrosynthesis

Enchant creature
Enchanted creature has "Whenever another creature dies, put a +1/+1 counter on this creature."
When enchanted creature dies, look at the top X cards of your library, where X is its power. Put one of those cards into your hand and the rest on the bottom of your library in a random order.

Baldur's Gate

{T}: Add {C}.
{2}, {T}: Add X mana of any one color, where X is the number of other Gates you control.

Tribute Mage

When Tribute Mage enters the battlefield, you may search your library for an artifact card with mana value 2, reveal that card, put it into your hand, then shuffle.

Indomitable Creativity

Destroy X target artifacts and/or creatures. For each permanent destroyed this way, its controller reveals cards from the top of their library until an artifact or creature card is revealed and exiles that card. Those players put the exiled cards onto the battlefield, then shuffle.

Painter's Servant

As Painter's Servant enters the battlefield, choose a color.
All cards that aren't on the battlefield, spells, and permanents are the chosen color in addition to their other colors.

Daretti, Scrap Savant

+2: Discard up to two cards, then draw that many cards.
−2: Sacrifice an artifact. If you do, return target artifact card from your graveyard to the battlefield.
−10: You get an emblem with "Whenever an artifact is put into your graveyard from the battlefield, return that card to the battlefield at the beginning of the next end step."
Daretti, Scrap Savant can be your commander.

Retraction Helix

Until end of turn, target creature gains "{T}: Return target nonland permanent to its owner's hand."

Graveshifter

Changeling (This card is every creature type.)
When Graveshifter enters the battlefield, you may return target creature card from your graveyard to your hand.

Circuitous Route

Search your library for up to two basic land cards and/or Gate cards, put them onto the battlefield tapped, then shuffle.

Wargate

Search your library for a permanent card with mana value X or less, put it onto the battlefield, then shuffle.

Inventors' Fair

At the beginning of your upkeep, if you control three or more artifacts, you gain 1 life.
{T}: Add {C}.
{4}, {T}, Sacrifice Inventors' Fair: Search your library for an artifact card, reveal it, put it into your hand, then shuffle. Activate only if you control three or more artifacts.

Crossroads Candleguide

When Crossroads Candleguide enters the battlefield, exile up to one target card from a graveyard.
{2}: Add one mana of any color.

Grindstone

{3}, {T}: Target player mills two cards. If two cards that share a color were milled this way, repeat this process.

Sun Titan

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

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Clever Impersonator

You may have Clever Impersonator enter the battlefield as a copy of any nonland permanent on the battlefield.

Gruul Guildgate

Gruul Guildgate enters the battlefield tapped.
{T}: Add {R} or {G}.

Sea Gate

Sea Gate enters the battlefield tapped.
As Sea Gate enters the battlefield, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Citadel Gate

Citadel Gate enters the battlefield tapped.
As Citadel Gate enters the battlefield, choose a color other than white.
{T}: Add {W} or one mana of the chosen color.

Birthing Boughs

{4}, {T}: Create a 2/2 colorless Shapeshifter creature token with changeling. (It has every creature type.)

Jousting Dummy

{3}: Jousting Dummy gets +1/+0 until end of turn.

Lightning Greaves

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

Heap Doll

Sacrifice Heap Doll: Exile target card from a graveyard.

Command Tower

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

Evolutionary Leap

{G}, Sacrifice a creature: Reveal cards from the top of your library until you reveal a creature card. Put that card into your hand and the rest on the bottom of your library in a random order.

Island

Overgrown Farmland

Overgrown Farmland enters the battlefield tapped unless you control two or more other lands.
{T}: Add {G} or {W}.

Farmstead Gleaner

Farmstead Gleaner doesn't untap during your untap step.
{2}, {Q}: Put a +1/+1 counter on Farmstead Gleaner. ({Q} is the untap symbol.)

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.

Plains

Orzhov Guildgate

Orzhov Guildgate enters the battlefield tapped.
{T}: Add {W} or {B}.

Padeem, Consul of Innovation

Artifacts you control have hexproof.
At the beginning of your upkeep, if you control the artifact with the highest mana value or tied for the highest mana value, draw a card.

Sudden Substitution

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Exchange control of target noncreature spell and target creature. Then the spell's controller may choose new targets for it.

Goblin Charbelcher

{3}, {T}: Reveal cards from the top of your library until you reveal a land card. Goblin Charbelcher deals damage equal to the number of nonland cards revealed this way to any target. If the revealed land card was a Mountain, Goblin Charbelcher deals double that damage instead. Put the revealed cards on the bottom of your library in any order.

Simic Guildgate

Simic Guildgate enters the battlefield tapped.
{T}: Add {G} or {U}.

Tezzeret, Master of the Bridge

Creature and planeswalker spells you cast have affinity for artifacts. (They cost {1} less to cast for each artifact you control.)
+2: Tezzeret, Master of the Bridge deals X damage to each opponent, where X is the number of artifacts you control. You gain X life.
−3: Return target artifact card from your graveyard to your hand.
−8: Exile the top ten cards of your library. Put all artifact cards from among them onto the battlefield.

Pili-Pala

Flying
{2}, {Q}: Add one mana of any color. ({Q} is the untap symbol.)

Swamp

Selesnya Guildgate

Selesnya Guildgate enters the battlefield tapped.
{T}: Add {G} or {W}.

Wild-Field Scarecrow

Defender
{2}, Sacrifice Wild-Field Scarecrow: Search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.

Vanquish the Horde

This spell costs {1} less to cast for each creature on the battlefield.
Destroy all creatures.

Scuttlemutt

{T}: Add one mana of any color.
{T}: Target creature becomes the color or colors of your choice until end of turn.

Boros Guildgate

Boros Guildgate enters the battlefield tapped.
{T}: Add {R} or {W}.

Mana Vault

Mana Vault doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault.
At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you.
{T}: Add {C}{C}{C}.

Golgari Guildgate

Golgari Guildgate enters the battlefield tapped.
{T}: Add {B} or {G}.

Splendid Reclamation

Return all land cards from your graveyard to the battlefield tapped.

Mountain

Eerie Interlude

Exile any number of target creatures you control. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

Banishing Knack

Forest

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Basilisk Gate

{T}: Add {C}.
{2}, {T}: Target creature gets +X/+X until end of turn, where X is the number of Gates you control. Activate only as a sorcery.

Spark Double

You may have Spark Double enter the battlefield as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Maze's End

Maze's End enters the battlefield tapped.
{T}: Add {C}.
{3}, {T}, Return Maze's End to its owner's hand: Search your library for a Gate card, put it onto the battlefield, then shuffle. If you control ten or more Gates with different names, you win the game.

Izzet Guildgate

Izzet Guildgate enters the battlefield tapped.
{T}: Add {U} or {R}.

Open the Gates

Search your library for a basic land card or Gate card, reveal it, put it into your hand, then shuffle.

Reckless Fireweaver

Whenever an artifact enters the battlefield under your control, Reckless Fireweaver deals 1 damage to each opponent.

Sol Ring

Master Transmuter

{U}, {T}, Return an artifact you control to its owner's hand: You may put an artifact card from your hand onto the battlefield.

Rite of Oblivion

As an additional cost to cast this spell, sacrifice a nonland permanent.
Exile target nonland permanent.
Flashback {2}{W}{B} (You may cast this card from your graveyard for its flashback cost and any additional costs. Then exile it.)

Reflections of Littjara

As Reflections of Littjara enters the battlefield, choose a creature type.
Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)

Mystic Monastery

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

Treasure Vault

{T}: Add {C}.
{X}{X}, {T}, Sacrifice Treasure Vault: Create X Treasure tokens.

Trophy Mage

When Trophy Mage enters the battlefield, you may search your library for an artifact card with mana value 3, reveal it, put it into your hand, then shuffle.

Masked Vandal

Changeling (This card is every creature type.)
When Masked Vandal enters the battlefield, you may exile a creature card from your graveyard. If you do, exile target artifact or enchantment an opponent controls.

Nettle Drone

Devoid (This card has no color.)
{T}: Nettle Drone deals 1 damage to each opponent.
Whenever you cast a colorless spell, untap Nettle Drone.

Scorn Effigy

Foretell {0} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Fabricate

Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

Grand Architect

Other blue creatures you control get +1/+1.
{U}: Target artifact creature becomes blue until end of turn.
Tap an untapped blue creature you control: Add {C}{C}. Spend this mana only to cast artifact spells or activate abilities of artifacts.

Glorious End

End the turn. (Exile all spells and abilities from the stack, including this card. The player whose turn it is discards down to their maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)
At the beginning of your next end step, you lose the game.