At the beginning of each upkeep, if a player cast two or more spells last turn, transform Merciless Predator.

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

Draw two cards.

Flying

Whenever you cast an instant or sorcery spell, Mercurial Geists gets +3/+0 until end of turn.

You may have Mercurial Pretender enter as a copy of a creature you control, except it has ": Return this creature to its owner's hand."

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.

Outlast (, : Put a +1/+1 counter on this creature. Outlast only as a sorcery.)

Each creature you control with a +1/+1 counter on it has deathtouch.

Whenever a creature you control explores, Merfolk Cave-Diver gets +1/+0 until end of turn and can't be blocked this turn.

, : Target player mills two cards.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

Phasing (This phases in or out before you untap during each of your untap steps. While it's phased out, it's treated as though it doesn't exist.)

Other Merfolk creatures you control get +1/+1.

: Target Merfolk creature can't be blocked this turn.

Flash

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

Flying

Whenever Merfolk Windrobber deals combat damage to a player, that player mills a card. (They put the top card of their library into their graveyard.)

Sacrifice Merfolk Windrobber: Draw a card. Activate only if an opponent has eight or more cards in their graveyard.

Whenever one or more Halflings you control attack a player, create a Food token. (It's an artifact with ", , Sacrifice this artifact: You gain 3 life.")

Merieke Ri Berit doesn't untap during your untap step.

: Gain control of target creature for as long as you control Merieke Ri Berit. When Merieke Ri Berit leaves the battlefield or becomes untapped, destroy that creature. It can't be regenerated.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

When Merrow Harbinger enters, you may search your library for a Merfolk card, reveal it, then shuffle and put that card on top.

When Merrow Witsniper enters, target player mills a card.

Partner with Pippin, Warden of Isengard (When this creature enters, target player may put Pippin into their hand from their library, then shuffle.)

Whenever one or more artifacts you control enter, create a 1/1 white Soldier creature token with lifelink. This ability triggers only once each turn.

Flying

When Mesa Cavalier enters, you gain 2 life.

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

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

All Slivers have "When this permanent enters, you may fateseal 1." (To fateseal 1, its controller looks at the top card of an opponent's library, then they may put that card on the bottom of that library.)

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.

When Metalspinner's Puzzleknot enters, you draw a card and you lose 1 life.

, Sacrifice Metalspinner's Puzzleknot: You draw a card and you lose 1 life.

Spree (Choose one or more additional costs.)

+ — Until end of turn, target creature becomes a white Rabbit with base power and toughness 0/1.

+ — Target player draws two cards.

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 Soldier can't be blocked.

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.)

Flying

Whenever you attack with one or more creatures with counters on them, draw a card.

Flying

: Metropolis Sprite gets +1/-1 until end of turn.

Whenever Mezzio Mugger attacks, exile the top card of each player's library. You may play those cards this turn, and you may spend mana as though it were mana of any color to cast those spells.

Blitz (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Flying

When Miasma Demon enters, you may discard any number of cards. When you do, up to that many target creatures each get -2/-2 until end of turn.

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.

: Surveil 1.

: Target permanent card in a graveyard becomes a 0/0 black Germ creature in addition to its other colors and types until end of turn. (This effect ends if it leaves the graveyard.)

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.