Afflict 2 (Whenever this creature becomes blocked, defending player loses 2 life.)

, Discard a card: Merciless Eternal gets +2/+2 until end of turn.

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

, : Draw two cards.

, , Discard a card: Mercurial Chemister deals damage to target creature equal to the discarded card's mana value.

Flying

Whenever Mercurial Kite deals combat damage to a creature, tap that creature. That creature doesn't untap during its controller's next untap step.

Until end of turn, target nonland permanent loses all abilities and becomes your choice of a blue Frog creature with base power and toughness 1/1 or a blue Octopus creature with base power and toughness 4/4.

Whenever another creature you control dies, you get an experience counter.

At the beginning of your end step, choose target creature card in your graveyard. If that card's mana value is less than or equal to the number of experience counters you have, return it to the battlefield. Otherwise, put it into your hand.

: Draw a card, then discard a card.

Other Merfolk you control get +1/+1.

: Switch target creature's power and toughness until end of turn.

Flash

When Merfolk Trickster enters, tap target creature an opponent controls. It loses all abilities until end of turn.

Reach

Domain — When Meria's Outrider enters, it deals damage to each opponent equal to the number of basic land types among lands you control.

, : Target creature gets -2/-0 until end of turn. ( is the untap symbol.)

When Merrow Witsniper enters, target player mills a card.

Counter target spell with mana value 3 or less. (Then exile this card. You may cast the creature later from exile.)

When Mesmerizing Benthid enters, create two 0/2 blue Illusion creature tokens with "Whenever this creature blocks a creature, that creature doesn't untap during its controller's next untap step."

Mesmerizing Benthid has hexproof as long as you control an Illusion.

Tap all artifacts.

As Metallic Mimic enters, choose a creature type.

Metallic Mimic is the chosen type in addition to its other types.

Each other creature you control of the chosen type enters with an additional +1/+1 counter on it.

Whenever you cast an instant or sorcery spell, create an X/X colorless Construct artifact creature token, where X is that spell's mana value.

, Exile Metallurgic Summonings: Return all instant and sorcery cards from your graveyard to your hand. Activate only if you control six or more artifacts.

This spell costs less to cast, where X is the total mana value of noncreature artifacts you control.

Sacrifice two artifacts: Return Metalwork Colossus from your graveyard to your hand.

Enchant creature

As Metamorphic Alteration enters, choose a creature.

Enchanted creature is a copy of the chosen creature.

Threshold — Metamorphic Wurm gets +4/+4 as long as seven or more cards are in your graveyard.

As an additional cost to cast this spell, sacrifice a creature.

Add X mana of any one color, where X is 1 plus the sacrificed creature's mana value. Spend this mana only to cast creature spells.

Whenever another nontoken creature you control enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Metathran Elite can't be blocked as long as it's enchanted.

Flying

Metathran Transport can't be blocked by blue creatures.

: Target creature becomes blue until end of turn.

Meteor Blast deals 4 damage to each of X targets.

When this creature enters, destroy target nonland permanent an opponent controls.

, Discard two cards at random: Meteor Storm deals 4 damage to any target.

Equipped creature gets +4/+0 and has trample.

Equip

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.)

(: Add or .)

Meticulous Archive enters tapped.

When Meticulous Archive enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

When a spell or ability an opponent controls causes you to discard Metrognome, create four 1/1 colorless Gnome artifact creature tokens.

, : Create a 1/1 colorless Gnome artifact creature token.

Flying, vigilance

You have hexproof.

Whenever Metropolis Reformer is dealt damage, you gain that much life.

(Transforms from Path of Mettle.)

: Add one mana of any color.

, : Metzali, Tower of Triumph deals 2 damage to each opponent.

, : Choose a creature at random that attacked this turn. Destroy that creature.

Whenever a source an opponent controls deals damage to you, that player sacrifices a permanent of your choice.

When Michonne enters, create two Walker tokens.

As long as Michonne is equipped, she must be blocked if able.

Whenever Michonne and at least two Zombies attack, she gains indestructible until end of turn.

When Midnight Arsonist enters, destroy up to X target artifacts without mana abilities, where X is the number of Vampires you control.

Wither (This deals damage to creatures in the form of -1/-1 counters.)

At the beginning of your upkeep, put a -1/-1 counter on each nonblack creature.

: Add .

: Put an hour counter on Midnight Clock.

At the beginning of each upkeep, put an hour counter on Midnight Clock.

When the twelfth hour counter is put on Midnight Clock, shuffle your hand and graveyard into your library, then draw seven cards. Exile Midnight Clock.

Midnight Entity — Whenever Midnight Crusader Shuttle attacks, defending player faces a villainous choice — That player sacrifices a creature of their choice, or you gain control of a creature of your choice that player controls until end of turn. If you gain control of a creature this way, tap it, and it's attacking that player.

Crew 2

Other Aetherborn you control get +1/+1.

Whenever Midnight Entourage or another Aetherborn you control dies, you draw a card and you lose 1 life.

Create two 1/1 white Spirit creature tokens with flying.

Midnight Oil enters with seven hour counters on it.

At the beginning of your draw step, draw an additional card and remove two hour counters from Midnight Oil.

Your maximum hand size is equal to the number of hour counters on Midnight Oil.

Whenever you discard a card, you lose 1 life.

Whenever a nontoken creature you control dies, this creature deals 1 damage to you and you draw a card.

Exile X target creature cards from your graveyard. For each creature card exiled this way, create a 2/2 black Zombie creature token.

Raid — At the beginning of your end step, if you attacked this turn, create a Food token. (It's an artifact with ", , Sacrifice this token: You gain 3 life.")

, Sacrifice this enchantment: Target opponent loses X life, where X is the amount of life you gained this turn.

Put two +1/+1 counters on target creature.

Delirium — Put three +1/+1 counters on that creature instead if there are four or more card types among cards in your graveyard.

Domain — Target creature gets +1/+1 until end of turn for each basic land type among lands you control.