Ancient Silver Dragon

Flying
Whenever Ancient Silver Dragon deals combat damage to a player, roll a d20. Draw cards equal to the result. You have no maximum hand size for the rest of the game.

Miirym, Sentinel Wyrm

Flying, ward {2}
Whenever another nontoken Dragon you control enters, create a token that's a copy of it, except the token isn't legendary.

Stormchaser Chimera

Flying
{2}{U}{R}: Scry 1, then reveal the top card of your library. Stormchaser Chimera gets +X/+0 until end of turn, where X is that card's mana value. (To scry 1, look at the top card of your library, then you may put that card on the bottom.)

Alhammarret's Archive

If you would gain life, you gain twice that much life instead.
If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Agent of Treachery

When Agent of Treachery enters, gain control of target permanent.
At the beginning of your end step, if you control three or more permanents you don't own, draw three cards.

Polymorph

Destroy target creature. It can't be regenerated. Its controller reveals cards from the top of their library until they reveal a creature card. The player puts that card onto the battlefield, then shuffles all other cards revealed this way into their library.

Archwing Dragon

Flying, haste
At the beginning of the end step, return Archwing Dragon to its owner's hand.

Monkey Cage

When a creature enters, sacrifice Monkey Cage and create X 2/2 green Monkey creature tokens, where X is that creature's mana value.

Counterspell

Forest

Wing Shredder

Reach
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Bird Admirer

Reach
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Bird Admirer // Wing Shredder

Goblin Anarchomancer

Each spell you cast that's red or green costs {1} less to cast.

Absorb Identity

Return target creature to its owner's hand. You may have Shapeshifters you control become copies of that creature until end of turn.

Exotic Orchard

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

Bounty of the Luxa

At the beginning of your first main phase, remove all flood counters from Bounty of the Luxa. If no counters were removed this way, put a flood counter on Bounty of the Luxa and draw a card. Otherwise, add {C}{G}{U}.

Overbeing of Myth

Overbeing of Myth's power and toughness are each equal to the number of cards in your hand.
At the beginning of your draw step, draw an additional card.

Book Burning

Any player may have Book Burning deal 6 damage to them. If no one does, target player mills six cards.

Mountain

Dampen Thought

Target player mills four cards.
Splice onto Arcane {1}{U} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

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.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Rejuvenating Springs

Rejuvenating Springs enters tapped unless you have two or more opponents.
{T}: Add {G} or {U}.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Simic Signet

Volo, Itinerant Scholar

When Volo enters, create Volo's Journal, a legendary colorless artifact token with hexproof and "Whenever you cast a creature spell, note one of its creature types that hasn't been noted for this artifact."
{2}, {T}: Draw a card for each creature type noted for target permanent you control named Volo's Journal.
Choose a Background

Beast Within

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

Rootbound Crag

Rootbound Crag enters tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Big Play

Target creature gets +2/+2 and gains reach until end of turn. Put a +1/+1 counter on it.

Arcane Signet

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

Masumaro, First to Live

Masumaro, First to Live's power and toughness are each equal to twice the number of cards in your hand.

Anger

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

Warstorm Surge

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

Rhythm of the Wild

Creature spells you control can't be countered.
Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Spire Garden

Spire Garden enters tapped unless you have two or more opponents.
{T}: Add {R} or {G}.

Haven of the Spirit Dragon

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a Dragon creature spell.
{2}, {T}, Sacrifice Haven of the Spirit Dragon: Return target Dragon creature card or Ugin planeswalker card from your graveyard to your hand.

Chameleon Colossus

Changeling (This card is every creature type.)
Protection from black
{2}{G}{G}: Chameleon Colossus gets +X/+X until end of turn, where X is its power.

Command Tower

Training Center

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

Sol Ring

Negate

Rockfall Vale

Rockfall Vale enters tapped unless you control two or more other lands.
{T}: Add {R} or {G}.

Druid of the Emerald Grove

When Druid of the Emerald Grove enters, search your library for up to two basic land cards and reveal them, then roll a d20.
9 or less | Put those cards into your hand, then shuffle.
10—19 | Put one of those cards onto the battlefield tapped and the other into your hand, then shuffle.
20+ | Put those cards onto the battlefield tapped, then shuffle.

Earthquake Dragon

This spell costs {X} less to cast, where X is the total mana value of Dragons you control.
Flying, trample
{2}{G}, Sacrifice a land: Return Earthquake Dragon from your graveyard to your hand.

Demanding Dragon

Flying
When Demanding Dragon enters, it deals 5 damage to target opponent unless that player sacrifices a creature.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Axgard Cavalry

{T}: Target creature gains haste until end of turn.

Ogre Battledriver

Whenever another creature you control enters, that creature gets +2/+0 and gains haste until end of turn. (It can attack and {T} this turn.)

Polymorphist's Jest

Until end of turn, each creature target player controls loses all abilities and becomes a blue Frog with base power and toughness 1/1.

Croaking Counterpart

Create a token that's a copy of target non-Frog creature, except it's a 1/1 green Frog.
Flashback {3}{G}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Boxing Ring

Whenever a creature you control enters, it fights up to one target creature you don't control with the same mana value.
{T}: Create a Treasure token. Activate only if you control a creature that fought this turn.

Pongify

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

Apex Altisaur

When Apex Altisaur enters, it fights up to one target creature you don't control.
Enrage — Whenever Apex Altisaur is dealt damage, it fights up to one target creature you don't control.

Evermind

(Nonexistent mana costs can't be paid.)
Draw a card.
Splice onto Arcane {1}{U} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Rampaging Baloths

Trample
Landfall — Whenever a land you control enters, you may create a 4/4 green Beast creature token.

Sublime Epiphany

Choose one or more —
• Counter target spell.
• Counter target activated or triggered ability.
• Return target nonland permanent to its owner's hand.
• Create a token that's a copy of target creature you control.
• Target player draws a card.

Mind Flayer

Dominate Monster — When Mind Flayer enters, gain control of target creature for as long as you control Mind Flayer.

Izzet Signet

Ghalta, Primal Hunger

This spell costs {X} less to cast, where X is the total power of creatures you control.
Trample

Gruul Signet

Imoti, Celebrant of Bounty

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Spells you cast with mana value 6 or greater have cascade.

Ketria Triome

({T}: Add {G}, {U}, or {R}.)
Ketria Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Wort, the Raidmother

When Wort, the Raidmother enters, create two 1/1 red and green Goblin Warrior creature tokens.
Each red or green instant or sorcery spell you cast has conspire. (As you cast the spell, you may tap two untapped creatures you control that share a color with it. When you do, copy it and you may choose new targets for the copy.)

Body of Knowledge

Body of Knowledge's power and toughness are each equal to the number of cards in your hand.
You have no maximum hand size.
Whenever Body of Knowledge is dealt damage, draw that many cards.

Steam Vents

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

Apex Devastator

Cascade, cascade, cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order. Multiple instances of cascade each trigger separately.)

Neverwinter Hydra

As Neverwinter Hydra enters, roll X d6. It enters with a number of +1/+1 counters on it equal to the total of those results.
Trample
Ward {4} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)

Island

Cinder Glade

({T}: Add {R} or {G}.)
Cinder Glade enters tapped unless you control two or more basic lands.

Dreamroot Cascade

Dreamroot Cascade enters tapped unless you control two or more other lands.
{T}: Add {G} or {U}.

Shadow in the Warp

The first creature spell you cast each turn costs {2} less to cast.
Whenever an opponent casts their first noncreature spell each turn, Shadow in the Warp deals 2 damage to that player.