Magus of the Arena

{3}, {T}: Tap target creature you control and target creature of an opponent's choice they control. Those creatures fight each other. (Each deals damage equal to its power to the other.)

Monkey Cage

When a creature enters, sacrifice Monkey Cage and create X 2/2 green Monkey creature tokens, where X is that creature's mana value.

Molten Influence

Counter target instant or sorcery spell unless its controller has Molten Influence deal 4 damage to them.

Mardu Heart-Piercer

Raid — When Mardu Heart-Piercer enters, if you attacked this turn, Mardu Heart-Piercer deals 2 damage to any target.

Foriysian Totem

{T}: Add {R}.
{4}{R}: Foriysian Totem becomes a 4/4 red Giant artifact creature with trample until end of turn.
As long as Foriysian Totem is a creature, it can block an additional creature each combat.

Moonsilver Spear

Equipped creature has first strike.
Whenever equipped creature attacks, create a 4/4 white Angel creature token with flying.
Equip {4}

Manakin

Magus of the Scroll

{3}, {T}: Choose a card name, then reveal a card at random from your hand. If that card has the chosen name, Magus of the Scroll deals 2 damage to any target.

Magma Jet

Magma Jet deals 2 damage to any target. Scry 2.

Mana Flare

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Maniacal Rage

Enchant creature
Enchanted creature gets +2/+2 and can't block.

Molten Disaster

Kicker {R} (You may pay an additional {R} as you cast this spell.)
If this spell was kicked, it has split second. (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Molten Disaster deals X damage to each creature without flying and each player.

Paradise Plume

As Paradise Plume enters, choose a color.
Whenever a player casts a spell of the chosen color, you may gain 1 life.
{T}: Add one mana of the chosen color.

Myr Retriever

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.

Myr Galvanizer

Other Myr creatures you control get +1/+1.
{1}, {T}: Untap each other Myr you control.

Prismatic Lens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Mogg War Marshal

Echo {1}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Mogg War Marshal enters or dies, create a 1/1 red Goblin creature token.

Shattering Pulse

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Destroy target artifact.

Pyroclasm

Pyroclasm deals 2 damage to each creature.

Spectral Searchlight

{T}: Choose a player. That player adds one mana of any color they choose.

Murasa Pyromancer

Whenever Murasa Pyromancer or another Ally you control enters, you may have Murasa Pyromancer deal damage to target creature equal to the number of Allies you control.

Magma Giant

When Magma Giant enters, it deals 2 damage to each creature and each player.

Mogg Assassin

{T}: You choose target creature an opponent controls, and that opponent chooses target creature. Flip a coin. If you win the flip, destroy the creature you chose. If you lose the flip, destroy the creature your opponent chose.

Mob Rule

Choose one —
• Gain control of all creatures with power 4 or greater until end of turn. Untap those creatures. They gain haste until end of turn.
• Gain control of all creatures with power 3 or less until end of turn. Untap those creatures. They gain haste until end of turn.

Monastery Swiftspear

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Mesmeric Orb

Whenever a permanent becomes untapped, that permanent's controller mills a card.

Tovolar's Magehunter

Whenever an opponent casts a spell, Tovolar's Magehunter deals 2 damage to that player.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Tovolar's Magehunter.

Mondronen Shaman

At the beginning of each upkeep, if no spells were cast last turn, transform Mondronen Shaman.

Mondronen Shaman // Tovolar's Magehunter

Megatog

Sacrifice an artifact: Megatog gets +3/+3 and gains trample until end of turn.

Mask of Avacyn

Equipped creature gets +1/+2 and has hexproof. (It can't be the target of spells or abilities your opponents control.)
Equip {3}

Mannichi, the Fevered Dream

{1}{R}: Switch each creature's power and toughness until end of turn.

Mirrorworks

Whenever another nontoken artifact you control enters, you may pay {2}. If you do, create a token that's a copy of that artifact.

Mordant Dragon

Flying
{1}{R}: Mordant Dragon gets +1/+0 until end of turn.
Whenever Mordant Dragon deals combat damage to a player, you may have it deal that much damage to target creature that player controls.

Moltensteel Dragon

({R/P} can be paid with either {R} or 2 life.)
Flying
{R/P}: Moltensteel Dragon gets +1/+0 until end of turn.

Mugging

Mugging deals 2 damage to target creature. That creature can't block this turn.

Manalith

Madblind Mountain

({T}: Add {R}.)
Madblind Mountain enters tapped.
{R}, {T}: Shuffle your library. Activate only if you control two or more red permanents.

Myojin of Infinite Rage

Myojin of Infinite Rage enters with a divinity counter on it if you cast it from your hand.
Myojin of Infinite Rage has indestructible as long as it has a divinity counter on it.
Remove a divinity counter from Myojin of Infinite Rage: Destroy all lands.

Mark of Mutiny

Gain control of target creature until end of turn. Put a +1/+1 counter on it and untap it. That creature gains haste until end of turn. (It can attack and {T} this turn.)

Millennial Gargoyle

Magmasaur

Magmasaur enters with five +1/+1 counters on it.
At the beginning of your upkeep, you may remove a +1/+1 counter from Magmasaur. If you don't, sacrifice Magmasaur and it deals damage equal to the number of +1/+1 counters on it to each creature without flying and each player.

Mercadian Atlas

At the beginning of your end step, if you didn't play a land this turn, you may draw a card.

Mind's Eye

Whenever an opponent draws a card, you may pay {1}. If you do, draw a card.

Manticore Eternal

Afflict 3 (Whenever this creature becomes blocked, defending player loses 3 life.)
Manticore Eternal attacks each combat if able.

Magmaw

{1}, Sacrifice a nonland permanent: Magmaw deals 1 damage to any target.

Molten Frame

Destroy target artifact creature.
Cycling {2} ({2}, Discard this card: Draw a card.)

Magma Vein

{R}, Sacrifice a land: Magma Vein deals 1 damage to each creature without flying.

Mogg Salvage

If an opponent controls an Island and you control a Mountain, you may cast this spell without paying its mana cost.
Destroy target artifact.

Mirari

Whenever you cast an instant or sorcery spell, you may pay {3}. If you do, copy that spell. You may choose new targets for the copy.

Mana Geyser

Add {R} for each tapped land your opponents control.

Mob Justice

Mob Justice deals damage to target player or planeswalker equal to the number of creatures you control.

Molten Primordial

Haste
When Molten Primordial enters, for each opponent, gain control of up to one target creature that player controls until end of turn. Untap those creatures. They gain haste until end of turn.

Mana Cylix

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Mindslaver

{4}, {T}, Sacrifice Mindslaver: You control target player during that player's next turn. (You see all cards that player could see and make all decisions for the player.)

Markov Blademaster

Double strike (This creature deals both first-strike and regular combat damage.)
Whenever Markov Blademaster deals combat damage to a player, put a +1/+1 counter on it.

Maw of Kozilek

Devoid (This card has no color.)
{C}: Maw of Kozilek gets +2/-2 until end of turn. ({C} represents colorless mana.)

Molten Hydra

{1}{R}{R}: Put a +1/+1 counter on Molten Hydra.
{T}, Remove all +1/+1 counters from Molten Hydra: It deals damage to any target equal to the number of +1/+1 counters removed this way.

Mountain

Millstone

Magma Spray

Magma Spray deals 2 damage to target creature. If that creature would die this turn, exile it instead.

Mogg Fanatic

Sacrifice Mogg Fanatic: It deals 1 damage to any target.

Myr Propagator

{3}, {T}: Create a token that's a copy of Myr Propagator.

Minotaur Aggressor

Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)

Manor Gargoyle

Defender
Manor Gargoyle has indestructible as long as it has defender.
{1}: Until end of turn, Manor Gargoyle loses defender and gains flying.

Mirrorpool

Mirrorpool enters tapped.
{T}: Add {C}.
{2}{C}, {T}, Sacrifice Mirrorpool: Copy target instant or sorcery spell you control. You may choose new targets for the copy.
{4}{C}, {T}, Sacrifice Mirrorpool: Create a token that's a copy of target creature you control.