In Bolas's Clutches

Enchant permanent
You control enchanted permanent.
Enchanted permanent is legendary.

Mutilate

All creatures get -1/-1 until end of turn for each Swamp you control.

Maro

Maro's power and toughness are each equal to the number of cards in your hand.

Blackmail

Target player reveals three cards from their hand and you choose one of them. That player discards that card.

Aura of Silence

Artifact and enchantment spells your opponents cast cost {2} more to cast.
Sacrifice this enchantment: Destroy target artifact or enchantment.

Nethroi, Apex of Death

Mutate {4}{G/W}{B}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Deathtouch, lifelink
Whenever this creature mutates, return any number of target creature cards with total power 10 or less from your graveyard to the battlefield.

Jester's Mask

This artifact enters tapped.
{1}, {T}, Sacrifice this artifact: Target opponent puts the cards from their hand on top of their library. Search that player's library for that many cards. That player puts those cards into their hand, then shuffles.

Arcane Signet

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

Jumbo Cactuar

10,000 Needles — Whenever this creature attacks, it gets +9999/+0 until end of turn.

Mind Games

Buyback {2}{U} (You may pay an additional {2}{U} as you cast this spell. If you do, put this card into your hand as it resolves.)
Tap target artifact, creature, or land.

Lowland Oaf

{T}: Target Goblin creature you control gets +1/+0 and gains flying until end of turn. Sacrifice that creature at the beginning of the next end step.

Giant Strength

Enchant creature
Enchanted creature gets +2/+2.

Island

Dream Cache

Draw three cards, then put two cards from your hand both on top of your library or both on the bottom of your library.

Amoeboid Changeling

Changeling (This card is every creature type.)
{T}: Target creature gains all creature types until end of turn.
{T}: Target creature loses all creature types until end of turn.

Plains

Reviving Dose

Eriette of the Charmed Apple

Each creature that's enchanted by an Aura you control can't attack you or planeswalkers you control.
At the beginning of your end step, each opponent loses X life and you gain X life, where X is the number of Auras you control.

Atog

Sacrifice an artifact: This creature gets +2/+2 until end of turn.

Forest

Head to Head

You and target opponent play Seven Questions with the top card of that player's library. If you win, prevent all damage that would be dealt this turn by a source of your choice. (To play Seven Questions, that player looks at the card, then you ask up to six yes-or-no questions about the card that they answer truthfully. You guess the card's name—that's question seven—then the player reveals the card.)

Putrefaction

Whenever a player casts a green or white spell, that player discards a card.

Deadhead

{0}: Return this card from your graveyard to the battlefield. Activate only if an opponent isn't touching their hand (of cards).

Incite

Target creature becomes red until end of turn and attacks this turn if able.

Nissa, Who Shakes the World

Whenever you tap a Forest for mana, add an additional {G}.
+1: Put three +1/+1 counters on up to one target noncreature land you control. Untap it. It becomes a 0/0 Elemental creature with vigilance and haste that's still a land.
−8: You get an emblem with "Lands you control have indestructible." Search your library for any number of Forest cards, put them onto the battlefield tapped, then shuffle.

Rapacious Dragon

Flying
When this creature enters, create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice this enchantment.
{B}: This enchantment deals 1 damage to each creature and each player.

Circle of Protection: Blue

{1}: The next time a blue source of your choice would deal damage to you this turn, prevent that damage.

Living Wall

Defender (This creature can't attack.)
{1}: Regenerate this creature.

Mad Prophet

Chromatic Orrery

You may spend mana as though it were mana of any color.
{T}: Add {C}{C}{C}{C}{C}.
{5}, {T}: Draw a card for each color among permanents you control.

Swamp

Chains of Mephistopheles

If a player would draw a card except the first one they draw in each of their draw steps, that player discards a card instead. If the player discards a card this way, they draw a card. If the player doesn't discard a card this way, they mill a card.

T.A.P.P.E.R.

{T}, Tap an untapped creature you control that has a hat: Tap target creature.

Skull Saucer

Flying
When this creature enters, destroy target creature and put your head on the table. Sacrifice this creature when your head stops touching the table.

Braids, Cabal Minion

At the beginning of each player's upkeep, that player sacrifices an artifact, creature, or land of their choice.

Balduvian Rage

Target attacking creature gets +X/+0 until end of turn.
Draw a card at the beginning of the next turn's upkeep.

Jester's Cap

{2}, {T}, Sacrifice this artifact: Search target player's library for three cards and exile them. Then that player shuffles.

Sensory Deprivation

Enchant creature
Enchanted creature gets -3/-0.

Mountain

Redeem

Prevent all damage that would be dealt this turn to up to two target creatures.

Captain Storm, Cosmium Raider

Whenever an artifact you control enters, put a +1/+1 counter on target Pirate you control.

Venerable Monk

When this creature enters, you gain 2 life.

Inside Out

Switch target creature's power and toughness until end of turn.
Draw a card.

Crawling Chorus

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
When this creature dies, create a 1/1 colorless Phyrexian Mite artifact creature token with toxic 1 and "This token can't block."

Sakura-Tribe Elder

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

Enfeeblement

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature gets -2/-2.

Morophon, the Boundless

Changeling (This card is every creature type.)
As Morophon enters, choose a creature type.
Spells of the chosen type you cast cost {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay.
Other creatures you control of the chosen type get +1/+1.

Rackling

At the beginning of each opponent's upkeep, this creature deals X damage to that player, where X is 3 minus the number of cards in their hand.

Frankenstein's Monster

As this creature enters, exile X creature cards from your graveyard. If you can't, put this creature into its owner's graveyard instead of onto the battlefield. For each creature card exiled this way, this creature enters with a +2/+0, +1/+1, or +0/+2 counter on it.

Sol Ring

Wicked Reward

As an additional cost to cast this spell, sacrifice a creature.
Target creature gets +4/+2 until end of turn.

Murderous Compulsion

Destroy target tapped creature.
Madness {1}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Gallia of the Endless Dance

Haste
Other Satyrs you control get +1/+1 and have haste.
Whenever you attack with three or more creatures, you may discard a card at random. If you do, draw two cards.

Johan

At the beginning of combat on your turn, you may have Johan gain "Johan can't attack" until end of combat. If you do, attacking doesn't cause creatures you control to tap this combat if Johan is untapped.

Thunderheads

Replicate {2}{U} (When you cast this spell, copy it for each time you paid its replicate cost.)
Create a 3/3 blue Weird creature token with defender and flying. Exile it at the beginning of the next end step.

Abbey Matron

{W}, {T}: This creature gets +0/+3 until end of turn.

Blistering Barrier

Stern Marshal

{T}: Target creature gets +2/+2 until end of turn. Activate only during your turn, before attackers are declared.

Serene Heart

Tendrils of Agony

Target player loses 2 life and you gain 2 life.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Massacre

If an opponent controls a Plains and you control a Swamp, you may cast this spell without paying its mana cost.
All creatures get -2/-2 until end of turn.

Keeper of the Light

{W}, {T}: Choose target opponent who has more life than you do as you activate this ability. You gain 3 life.

Karn, the Great Creator

Activated abilities of artifacts your opponents control can't be activated.
+1: Until your next turn, up to one target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value.
−2: You may reveal an artifact card you own from outside the game or choose a face-up artifact card you own in exile. Put that card into your hand.