Soulmates

Enchant two creatures
Enchanted creatures each get +1/+1 and have hexproof.
When one of the enchanted creatures dies, destroy the other.

Wrath of Sod

Put a manabond counter on all creatures. (They lose all other abilities and become lands with "{T}: Add one mana of this card's color.")

Barry's Land

Puresteel Angel

Flying, indestructible
When Puresteel Angel enters, exile all artifacts that aren't colorless.
Whenever Puresteel Angel deals combat damage to a player, you get an emblem with "If you would lose the game, instead your life total becomes 20, shuffle your graveyard into your library, you lose all poison counters, and you lose this emblem."

Bombardment

Until end of turn, cards you own that aren't on the battlefield lose all card types, costs, names, and abilities and become red sorceries named Missile that cost {R} with "Missile deals 2 damage to any target."

Learned Learner

As long as you have a maximum hand size other than 7, Learned Learner has "{T}: Draw a card."

Plane-Merge Elf

Landship — At the beginning of your upkeep, you may look at the top card of your library. If it's a land, you may reveal it. If you do, create a 1/1 green Elf Warrior creature token.
Kinfall — Whenever a creature enters the battlefield under your control, if it shares a creature type with Plane-Merge Elf, creatures you control get +1/+1 until end of turn.

Jasconian Isle

(Jasconian Isle isn't a spell, it's affected by summoning sickness, it's blue, and it has "{T}: Add {U}.")
Jasconian Isle enters tapped.
Jasconian Isle doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {U}{U}. If you do, untap Jasconian Isle.

Pithing Spyglass

As Pithing Spyglass enters, name a keyword ability or ability word.
All cards in all zones lose that keyword ability or ability word and all text tied to that ability.

Baneslayer Aspirant

Baneslayer Aspirant gets +3/+3 and has flying, first strike, and lifelink as long as you have one or more emblems.

Truth or Dare

Target opponent chooses one —
• Truth — That player plays with their hand revealed for the rest of the game.
• Dare — Mill all but the bottom ten cards of that player's library. (To mill, put the top card of that library into its owner's graveyard.)

Sliv-Mizzet, Hivemind

Slivers you control have flying and "Whenever you draw a card, this creature deals 1 damage to any target" and "{T}: Draw a card."

Gorilla Tactics

Create a 2/2 green Gorilla creature token.
When a spell or ability an opponent controls causes you to discard Gorilla Tactics, create two 2/2 green Gorilla creature tokens.

Bear with Set's Mechanic

Vigilance
Aggressive (During your turn, there is an additional combat phase after the first, and only creatures with aggressive may attack during it.)

Loopy Lobster

Four-faced (Whenever this becomes tapped, move it to the next stage, or to stage 1 if it's at stage 4.)
Stage 1 — (1/4)
Stage 2 — (4/1) Evolve
Stage 3 — (2/4) {U}: Loopy Lobster gets +1/-1 until end of turn.
Stage 4 — (4/4) Vigilance. {T}: Draw 2 cards.

Domesticated Watercourse

Domesticated Watercourse enters tapped.
{T}: Add {U} or {B}.
{U}{B}: Until end of turn, Domesticated Watercourse becomes an Equipment artifact with equip {2}.
Whenever equipped creature deals combat damage to a player, draw a card.

Liberate

Exile target creature you control. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Bind

Counter target activated ability. (Mana abilities can't be targeted.)
Draw a card.

Bind // Liberate

Enchanted Prairie

Enchanted Prairie enters tapped.
{T}: Add {W} or {U}.

Five Kids in a Trenchcoat

Five Kids in a Trenchcoat counts as five creatures for spells and effects that count the number of creatures you control.

Throat Wolf

You may cast Throat Wolf during an opponent's combat phase.
Firstest strike (This creature deals combat damage to creatures before creatures with first strike.)
After each opponent's first combat phase of each turn, there is an additional combat phase. Only Throat Wolf can attack during that combat phase.

Geometric Weird

At the beginning of each end step, you may have Geometric Weird's base power and toughness each become equal to the greatest number of spells and abilities from different sources that were on the stack simultaneously that turn.

How to Keep an Izzet Mage Busy

Return How to Keep an Izzet Mage Busy to its owner's hand.

Buried Ogre

You may begin the game with Buried Ogre in your graveyard. If you do, you lose 1 life.

Do-Over

Restart the turn, except with Do-Over in exile. (First, return all cards to where they were as the turn began. For information from hidden zones like the hand, reconstruct as best you can, and do the rest at random.)

Stack of Paperwork

When Stack of Paperwork enters, draw a card.
Combat damage uses the stack. (Combat damage assignment can be responded to before damage is dealt.)

Mana Abundance

If a player would add mana, instead all players add that mana.

Domesticated Mammoth

Domesticated Mammoth enters with a token copy of Pacifism attached to it.

Frenemy of the Guildpact

Protection from enemy-colored multicolored (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything that's two enemy colors, such as blue and green.)

Memory Bank

Draw a card.
Bank (If you cast Memory Bank from your hand, exile it until the end of the match. You may cast it from exile during another game this match. It still counts toward your deck minimum.)

Planequake

Planequake deals X damage to each creature without flying and each planeswalker. If X is 10 or more, open the "Uncovered Cavern" plot booster.

Innocuous Insect

Buyback {1}{U} (You may pay an additional {1}{U} as you cast this spell. If you do, put this card into your hand as it resolves.)
Flash
Flying
When you cast this spell, draw a card.

Recycla-bird

Flying
When Recycla-bird dies, put a flying counter on target creature you control.

Wizened Arbiter

When Wizened Arbiter enters, you may reveal a white card you own from outside the game. If you do, exchange that card with a card in your hand.

Visitor from Planet Q

All creature cards you own with flash are instants in addition to their other types.
Whenever you cast another spell with two or more card types, you may draw a card, then discard a card.

Cyclopean Titan

When Cyclopean Titan dies, two target lands become Swamps. Exile Cyclopean Titan.
{3}, {T}: Tap target creature, then return Cyclopean Titan to its owner's hand.

Graveyard Dig

Return up to two target [black or green] creature cards from your graveyard to your hand.
You may cast this spell for {2}{B/G}{B/G}. If you do, ignore the bracketed text.

Destroy target creature. Its controller creates two 1/2 red Half creature tokens.

Smelt

Smelt // Herd // Saw

Zyym, Mesmeric Lord

Flying, deathtouch
When Zyym, Mesmeric Lord enters the battlefield, target opponent chooses an order for the cards in their hand, then reveals them one by one until you say stop. That player then discards the most recently revealed card.

Red Herring

{1}{U}: Exchange Red Herring from your hand with a permanent you control on the battlefield or a spell you control on the stack. If that permanent or spell was the target of a spell or ability, change that target to Red Herring.

You're in Command

Choose target creature you own and control. That creature becomes your commander. Any other commanders you have are no longer your commander. (That creature starts with a commander tax of {0}.)

Slivdrazi Monstrosity

Eldrazi you control are Slivers in addition to their other types.
Slivers you control have devoid and annihilator 1.
{3}: Create a 1/1 colorless Eldrazi Sliver creature token. It has "Sacrifice this creature: Add {C}."

Interplanar Brushwagg

Interplanar (This creature enters onto the interplanar battlefield. Players can't control creatures on the interplanar battlefield.)
Vigilance, haste
Whenever a player attacks with a creature with power 4 or greater, Interplanar Brushwagg also attacks the player or planeswalker that creature is attacking.

Patient Turtle

Patient Turtle enters with two +1/+1 counters on it if you didn't go first this game.

Gold Mine

{T}: Add {C}.
Legacy — {T}, Mark one of Gold Mine's unmarked nodes: Add one mana of any color.
☐, ☐, ☐, ☐, ☐

A Good Thing

Spells and abilities you control can't destroy, exile, target, or cause you to sacrifice A Good Thing.
At the beginning of your upkeep, double your life total. Then, if you have 1,000 or more life, you lose the game.

Celestine Cave Witch

When Celestine Cave Witch enters, create two 1/1 black Insect creature tokens.
Whenever Celestine Cave Witch attacks, you may sacrifice an Insect. When you do, curse defending player. (Create a black Aura Curse enchantment token that's attached to that player. It has enchant player and "At the beginning of your upkeep, you lose 1 life.")

Inspirational Antelope

Legacy — Before the game starts, choose a keyword or ability word and write it below.
Spells with __________ you cast cost {1} less to cast.

Control Win Condition

This spell can't be countered.
Shroud
Control Win Condition's power and toughness are each equal to the number of turns you've taken this game. (If this is in your deck, please keep track of your turns. This means you, Mark.)

Sunimret

Reverse miracle {B} (If this card is on the bottom of your library as you begin searching it, you may cast it by paying its reverse miracle cost.)
Exile all creatures.

Witty Demon

Flying
When Witty Demon enters, if your starting library had at least 13 cards over the minimum, search your library for a card and put that card into your hand, then shuffle your library. Otherwise, Witty Demon deals 4 damage to you.

Noxious Bayou

{T}: Add {B} or {G}. You get a poison counter.

Experiment Five

{1}{Z}: Put a +1/+2 counter on Experiment Five. ({Z} is paid with one mana from any source that could produce two or more colors of mana.)

Metagamer

Cards in the winning deck(s) of the latest Mythic Championship cost {1} more to cast.

Taiga Stadium

Taiga Stadium enters tapped unless you control a white, blue, or black permanent.
{T}: Add {R} or {G}.

Trial and Error

Whenever Trial and Error is countered or fizzles, you may copy it and choose new targets for the copy.
Trial and Error deals 3 damage to any target.

Waste Land

{T}: Add {C}.
{T}, Sacrifice Waste Land: Destroy target nonbasic land. That land's controller creates a Wastes token. (It's a land with {T}: Add {C}.)

Corrupted Key

As long as Corrupted Key is tapped, creatures you control have menace and deathtouch.

Priority Avenger

Flying
Players can't cast instant spells unless a spell or ability is on the stack.

Command the Chaff

Look at target opponent's sideboard. You may cast a card from that sideboard without paying its mana cost.
Exile Command the Chaff.

Form of the Mulldrifter

When Form of the Mulldrifter enters, draw two cards.
You may cast creature cards from your hand as though they were the card Mulldrifter. (You can still evoke this way. They're Mulldrifters.)

Enroll in the Coalition

You are a Flagbearer.
While choosing targets as part of casting a spell or activating an ability, your opponents must choose at least one Flagbearer if able.

Siege Elemental

Trample
Untapped creatures can't block.
Tapped creatures can block.

Mirrored Lotus

Reflect {0} (As this enters, each opponent may pay {0}. When they do, they create a token copy of this except it lacks this ability.)
{T}, Exile Mirrored Lotus: Add three mana of any one color.

Squidnapper

When Squidnapper enters, gain control of target creature an opponent controls until Squidnapper leaves the battlefield or that player pays the ransom.
Ransom — {6} and 2 life

Imaginary Friends

Create three 0/0 white Spirit creature tokens with flying.

Largepox

Each player discards a card, then loses 1 life, then sacrifices an artifact, a creature, an enchantment, a land, a planeswalker, and a tribal permanent, then exiles a card from their graveyard, then puts the top card of their library into their graveyard, then removes a counter from a permanent they control, then gets a poison counter.

Enchantmentize

Enchant creature or enchantment
Enchanted permanent is an enchantment and loses all other card types. (It still has its abilities, but it's no longer a creature.)

Chronobot

When Chronobot enters, switch upkeep steps with target opponent for as long as it remains on the battlefield. (You take your upkeep on their turn, and they take their upkeep on your turn.)

Scaled Destruction

Choose one or more —
• Destroy all small creatures.
• Destroy all medium creatures.
• Destroy all large creatures.
(A small creature has total power and toughness 4 or less, medium is 5—8, and large is 9 or more.)

Frontier Explorer

{3}, {T}: Until end of turn, you may play one basic Plains card from outside the game.

Seasoned Weaponsmith

Tasty (This creature can be attacked directly. If it is attacked, it can't block creatures that didn't attack it.)

Generated Horizons

At the beginning of your upkeep, create a Forest land token.

Weaponized Scrap

Upgrade (This creature enters covering another artifact you control. If it can't, exile it. Ignore the artifact it's covering. Anywhere this card goes, cards underneath it also go. It has haste.)

Lantern of Undersight

You draw cards from the bottom of your library instead of the top of your library.

Sarah's Wings

Target creature or player gains flying until end of turn. (Players with flying can't be dealt damage by creatures without flying.)

Unicycle

First strike, haste
Equipped creature has first strike and haste.
Equip {1}
Crew 1

Xyru Specter

Flying
Whenever Xyru Specter deals damage to an opponent, that player discards a card unless they challenge you. If challenged, and you show them two black cards in your hand, they must discard two cards.

Lazier Goblin

Motivate {3}{R} (This creature can't attack or block unless you have paid its motivate cost once. Motivate only as a sorcery.)
When Lazier Goblin enters, it deals 2 damage to any target.

The Grand Tour

Exile target permanent, then put it into its owner's hand. That player discards that card, then puts it on top of their library. Then they put it onto the battlefield.

Problematic Volcano

When Problematic Volcano enters, it deals 4 damage to any target. Then, starting with you, each player assigns their creatures to the left or right of the volcano. Creatures enter to the left or right of the volcano.
Creatures can't block creatures on the other side of the volcano.

Transcantation

Target instant or sorcery spell becomes a copy of Lightning Bolt. Its controller may choose new targets for it.

Yawgmoth's Testament

Until end of turn, you may play face-up cards you own from exile.
If a card would be put into your graveyard or exile from anywhere this turn, put it on the bottom of your library instead.

Animate Spell

Flash
Enchant instant or sorcery spell on the stack
When Animate Spell becomes attached to an instant or sorcery, put that card onto the battlefield under its owner's control. It's a creature in addition to its other types with power and toughness each equal to its converted mana cost.
When Animate Spell leaves the battlefield, enchanted card's owner sacrifices it unless they cast it.

Underdark Beholder

Underdark Beholder enters the battlefield with ten eyestalk counters on it.
If Underdark Beholder would be dealt damage, remove that many eyestalk counters from it instead. If you can't, sacrifice it.
Whenever Underdark Beholder attacks, reveal cards from the top of your library until you reveal an instant, sorcery, or enchantment card with converted mana cost less than the number of eyestalk counters on Underdark Beholder. You may cast it without paying its mana cost. Shuffle your library.

Louvaq, the Aberrant

Protection from modified creatures (Modified creatures have a power, toughness, or ability different than their printed versions.)
At the beginning of each player's end step, you may put a +1/+1 counter on target creature that player controls.

Everlasting Lich

Everlasting Lich can't block.
Everlasting Lich can't die. (This creature has indestructible, can't be sacrificed, and doesn't go to the graveyard for having 0 toughness.)

Spellmorph Raise Dead

Return target creature card from your graveyard to your hand.
Spellmorph {B} (You may cast this card face down as a 2/2 creature for {3}. Cast it any time for its spellmorph cost.)

Blood Poet

Spark (Activate spark abilities by spending or giving yourself spark counters. Activate only one spark ability per turn, and only as a sorcery.)
+1: Blood Poet gains lifelink until end of turn.
−3: Target opponent discards a card. You gain life equal to its converted mana cost.

Queue of Beetles

Haste
The stack is now first in, first out instead of last in, first out. (The first spell or ability on the stack is the first one to resolve.)

Tibalt the Chaotic

+1: Cast a copy of one of the following cards chosen at random—Ignorant Bliss, Crack the Earth, Blazing Volley.
−3: Cast a copy of one of the following cards chosen at random—Seething Song, Dance with Devils, Flamebreak.
−6: Cast a copy of one of the following cards chosen at random—Hellion Eruption, Insurrection, Warp World.

One with Death

Kaya, Ghost Haunter

0: Exile Kaya, Ghost Haunter haunting target creature for as long as that creature remains on the battlefield.
−1: You get an emblem with, "At the beginning of your upkeep, this emblem deals 3 damage to the owner of target haunted creature."
−2: You get an emblem with, "At the beginning of your upkeep, gain control of target haunted creature for as long as it remains haunted."

Frogkin Kidnapper

When Frogkin Kidnapper enters, target opponent reveals their hand. Choose a nonland card from it. Ransom that card. (Exile it. Its owner may pay {3} at any time to return it to their hand.)

Ruff, Underdog Champ

All Hounds are Dogs. (We'll errata this to be true.)
First strike, lifelink
Underdog — If you've lost a game this match, Ruff, Underdog Champ and other Dogs you control get +1/+1.

Abian, Luvion Usurper

As Abian, Luvion Usurper enters, you become Abian. (Your life total becomes equal to their loyalty. You can activate the loyalty abilities by spending or gaining life.)
+3: Discard your hand, then draw cards equal to the greatest power among creatures you control.
+1: Create a 3/2 red and green Spirit creature token.
−X: You deal X damage to any target.

Fire

Fire deals 2 damage divided as you choose among one or two targets.

Start

Create two 1/1 white Warrior creature tokens with vigilance.

Start // Fire

Swarm of Locus

Flying
Whenever Swarm of Locus attacks, it gets +1/+0 until end of turn for each Locus you control.

High Troller

All targeted spells and abilities cost {2} less and have their targets chosen randomly.