Master of Predicaments

Flying
Whenever this creature deals combat damage to a player, choose a card in your hand. That player guesses whether the card's mana value is greater than 4. If the player guessed wrong, you may cast the card without paying its mana cost.

Fellwar Stone

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

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.

Dream Devourer

Each nonland card in your hand without foretell has foretell. Its foretell cost is equal to its mana cost reduced by {2}. (During your turn, you may pay {2} and exile it from your hand face down. Cast it on a later turn for its foretell cost.)
Whenever you foretell a card, this creature gets +2/+0 until end of turn.

Command Tower

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

Island

Cleansing Nova

Choose one —
• Destroy all creatures.
• Destroy all artifacts and enchantments.

Varragoth, Bloodsky Sire

Deathtouch
Boast — {1}{B}: Target player searches their library for a card, then shuffles and puts that card on top. (Activate only if this creature attacked this turn and only once each turn.)

Time Wipe

Return a creature you control to its owner's hand, then destroy all creatures.

Noble Benefactor

When this creature dies, each player may search their library for a card and put that card into their hand. Then each player who searched their library this way shuffles.

Petra Sphinx

{T}: Target player chooses a card name, then reveals the top card of their library. If that card has the chosen name, that player puts it into their hand. If it doesn't, the player puts it into their graveyard.

Godless Shrine

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

Drana, the Last Bloodchief

Flying
Whenever Drana attacks, defending player chooses a nonlegendary creature card in your graveyard. You return that card to the battlefield with an additional +1/+1 counter on it. The creature is a Vampire in addition to its other types.

Fleshbag Marauder

When this creature enters, each player sacrifices a creature of their choice.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Sword of Feast and Famine

Equipped creature gets +2/+2 and has protection from black and from green.
Whenever equipped creature deals combat damage to a player, that player discards a card and you untap all lands you control.
Equip {2}

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Doom Whisperer

Flying, trample
Pay 2 life: Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Crashing Drawbridge

Defender
{T}: Creatures you control gain haste until end of turn.

Skycloud Expanse

Lim-Dûl's Vault

Look at the top five cards of your library. As many times as you choose, you may pay 1 life, put those cards on the bottom of your library in any order, then look at the top five cards of your library. Then shuffle and put the last cards you looked at this way on top in any order.

Kaya's Ghostform

Enchant creature or planeswalker you control
When enchanted permanent dies or is put into exile, return that card to the battlefield under your control.

Spy Network

Look at target player's hand, the top card of that player's library, and any face-down creatures they control. Look at the top four cards of your library, then put them back in any order.

Temple of Deceit

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {U} or {B}.

Exotic Orchard

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.)

Liar's Pendulum

{2}, {T}: Choose a card name. Target opponent guesses whether a card with that name is in your hand. You may reveal your hand. If you do and your opponent guessed wrong, draw a card.

Temple of Silence

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {W} or {B}.

Scheming Symmetry

Choose two target players. Each of them searches their library for a card, then shuffles and puts that card on top.

Head Games

Target opponent puts the cards from their hand on top of their library. Search that player's library for that many cards. The player puts those cards into their hand, then shuffles.

Sphinx Ambassador

Flying
Whenever this creature deals combat damage to a player, search that player's library for a card, then that player chooses a card name. If you searched for a creature card that doesn't have that name, you may put it onto the battlefield under your control. Then that player shuffles.

Mortuary Mire

This land enters tapped.
When this land enters, you may put target creature card from your graveyard on top of your library.
{T}: Add {B}.

Choice of Damnations

Target opponent chooses a number. You may have that player lose that much life. If you don't, that player sacrifices all but that many permanents of their choice.

Reconnaissance

{0}: Remove target attacking creature you control from combat and untap it. (If you activate during end of combat, the creature will untap after it deals combat damage.)

Magister Sphinx

Flying
When this creature enters, target player's life total becomes 10.

Sol Ring

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Perplex

Counter target spell unless its controller discards their hand.
Transmute {1}{U}{B} ({1}{U}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Arcane Signet

Arcane Sanctum

This land enters tapped.
{T}: Add {W}, {U}, or {B}.

Soul Snare

{W}, Sacrifice this enchantment: Exile target creature that's attacking you or a planeswalker you control.

Hallowed Fountain

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

Temple of Enlightenment

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {W} or {U}.

Caves of Koilos

{T}: Add {C}.
{T}: Add {W} or {B}. This land deals 1 damage to you.

Swamp

Vega, the Watcher

Flying
Whenever you cast a spell from anywhere other than your hand, draw a card.

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Plains

Soothsaying

{3}{U}{U}: Shuffle your library.
{X}: Look at the top X cards of your library, then put them back in any order.

Brilliant Ultimatum

Exile the top five cards of your library. An opponent separates those cards into two piles. You may play lands and cast spells from one of those piles. If you cast a spell this way, you cast it without paying its mana cost.

Spark Double

You may have this creature enter 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.

Generous Gift

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

Yennett, Cryptic Sovereign

Flying, vigilance, menace
Whenever Yennett attacks, reveal the top card of your library. You may cast it without paying its mana cost if its mana value is odd. If you don't cast it, draw a card.

Orzhov Advokist

At the beginning of your upkeep, each player may put two +1/+1 counters on a creature they control. If a player does, creatures that player controls can't attack you or planeswalkers you control until your next turn.

Strionic Resonator

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

Azorius Signet

Thassa, God of the Sea

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
At the beginning of your upkeep, scry 1.
{1}{U}: Target creature you control can't be blocked this turn.

Portent

Look at the top three cards of target player's library, then put them back in any order. You may have that player shuffle.
Draw a card at the beginning of the next turn's upkeep.

Archfiend of Depravity

Flying
At the beginning of each opponent's end step, that player chooses up to two creatures they control, then sacrifices the rest.

Mirage Mirror

{2}: This artifact becomes a copy of target artifact, creature, enchantment, or land until end of turn.

Truth or Tale

Reveal the top five cards of your library and separate them into two piles. An opponent chooses one of those piles. Put a card from the chosen pile into your hand, then put all other cards revealed this way on the bottom of your library in any order.

Watery Grave

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

Gilded Lotus

Sage Owl

Flying
When this creature enters, look at the top four cards of your library, then put them back in any order.

Darkwater Catacombs

Riddlekeeper

Whenever a creature attacks you or a planeswalker you control, that creature's controller mills two cards.

Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

Terramorphic Expanse

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

Conundrum Sphinx

Flying
Whenever this creature attacks, each player chooses a card name. Then each player reveals the top card of their library. If the card a player revealed has the name they chose, that player puts it into their hand. If it doesn't, that player puts it on the bottom of their library.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Fight or Flight

At the beginning of combat on each opponent's turn, separate all creatures that player controls into two piles. Only creatures in the pile of their choice can attack this turn.

Penance

Put a card from your hand on top of your library: The next time a black or red source of your choice would deal damage this turn, prevent that damage.

Halimar Depths

This land enters tapped.
When this land enters, look at the top three cards of your library, then put them back in any order.
{T}: Add {U}.

Esper Charm

Choose one —
• Destroy target enchantment.
• Draw two cards.
• Target player discards two cards.

Crib Swap

Changeling (This card is every creature type.)
Exile target creature. Its controller creates a 1/1 colorless Shapeshifter creature token with changeling.

Fatespinner

At the beginning of each opponent's upkeep, that player chooses draw step, main phase, or combat phase. The player skips each instance of the chosen step or phase this turn.

Fatal Lore

An opponent chooses one —
• You draw three cards.
• You destroy up to two target creatures that player controls. They can't be regenerated. That player draws up to three cards.

Emrakul, the Promised End

This spell costs {1} less to cast for each card type among cards in your graveyard.
When you cast this spell, you gain control of target opponent during that player's next turn. After that turn, that player takes an extra turn.
Flying, trample, protection from instants

Aminatou, the Fateshifter

+1: Draw a card, then put a card from your hand on top of your library.
−1: Exile another target permanent you own, then return it to the battlefield under your control.
−6: Choose left or right. Each player gains control of all nonland permanents other than Aminatou controlled by the next player in the chosen direction.
Aminatou, the Fateshifter can be your commander.

Mulldrifter

Flying
When this creature enters, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Crystal Ball

{1}, {T}: Scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Evolving Wilds

Geode Golem

Trample
Whenever this creature deals combat damage to a player, you may cast your commander from the command zone without paying its mana cost. (You still pay any additional costs.)

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.