Flying, trample

Join forces — Whenever Mana-Charged Dragon attacks or blocks, each player starting with you may pay any amount of mana. Mana-Charged Dragon gets +X/+0 until end of turn, where X is the total amount of mana paid this way.

Afflict 3 (Whenever this creature becomes blocked, defending player loses 3 life.)

Manticore Eternal attacks each combat if able.

: Mantis Engine gains flying until end of turn. (It can't be blocked except by creatures with flying or reach.)

: Mantis Engine gains first strike until end of turn. (It deals combat damage before creatures without first strike.)

Flying, vigilance, ward

Whenever you commit a crime, surveil 2. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

All Walls able to block Marble Priest do so.

Prevent all combat damage that would be dealt to Marble Priest by Walls.

Whenever Mardu Roughrider attacks, target creature can't block this turn.

Fabricate 3 (When this creature enters the battlefield, put three +1/+1 counters on it or create three 1/1 colorless Servo artifact creature tokens.)

Whenever an artifact you control is put into a graveyard from the battlefield, target opponent loses life equal to Marionette Master's power.

Lifelink

Markov Crusader has haste as long as you control another Vampire.

Whenever Markov Enforcer or another Vampire enters the battlefield under your control, Markov Enforcer fights up to one target creature an opponent controls.

Whenever a creature dealt damage by Markov Enforcer this turn dies, create a Blood token. (It's an artifact with ", , Discard a card, Sacrifice this artifact: Draw a card.")

Double strike

Master Tactician — Whenever one or more tokens enter the battlefield under your control, draw a card.

Chapter Master — : Create two 2/2 white Astartes Warrior creature tokens with vigilance.

Devour 2 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with twice that many +1/+1 counters on it.)

When Marrow Chomper enters the battlefield, you gain 2 life for each creature it devoured.

Megamorph (You may cast this card face down as a 2/2 creature for . Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Flying

, : Rather than pay the mana cost of the next spell you cast this turn, you may pay life equal to that spell's mana value.

As long as Martyrs of Korlis is untapped, all damage that would be dealt to you by artifacts is dealt to Martyrs of Korlis instead.

Whenever Marvo, Deep Operative attacks, clash with defending player. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

Whenever you win a clash, draw a card. Then you may cast a spell from your hand with mana value 8 or less without paying its mana cost.

Vigilance

Menace (This creature can't be blocked except by two or more creatures.)

, Exile Masked Bandits from your hand: Target land gains ": Add , , or " until Masked Bandits is cast from exile. You may cast Masked Bandits for as long as it remains exiled.

Creatures you control have wither.

Whenever a creature an opponent controls dies, if it had 0 or less toughness, you and that player lose 1 life and you draw a card.

: Prevent the next 4 damage that would be dealt to any target this turn.

Flying

Whenever Master of Predicaments 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.

Masumaro, First to Live's power and toughness are each equal to twice the number of cards in your hand.

When Maul Splicer enters the battlefield, create two 3/3 colorless Phyrexian Golem artifact creature tokens.

Golem creatures you control have trample.

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for .)

When Maverick Thopterist enters the battlefield, create two 1/1 colorless Thopter artifact creature tokens with flying.

Flying

: Mawcor deals 1 damage to any target.

Trample

Multicolored creatures you control have trample.

Haste

Multicolored creatures you control have haste.

Flying

Whenever a player sacrifices another permanent, put a +1/+1 counter on each creature you control.

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

Whenever Meandering Towershell attacks, exile it. Return it to the battlefield under your control tapped and attacking at the beginning of the declare attackers step on your next turn.

Flying

Whenever Medomai the Ageless deals combat damage to a player, take an extra turn after this one.

Medomai the Ageless can't attack during extra turns.

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

Vigilance, trample

Whenever Meglonoth blocks a creature, Meglonoth deals damage to that creature's controller equal to Meglonoth's power.

Melek, Reforged Researcher's power and toughness are each equal to twice the number of instant and sorcery cards in your graveyard.

The first instant or sorcery spell you cast each turn costs less to cast.

Melira's Keepers can't have counters put on it.

: Target permanent becomes an artifact in addition to its other types. (This effect lasts indefinitely.)

: Gain control of target artifact. (This effect lasts indefinitely.)

Trample, haste

When Menacing Ogre enters the battlefield, each player secretly chooses a number. Then those numbers are revealed. Each player with the highest number loses that much life. If you are one of those players, put two +1/+1 counters on Menacing Ogre.

Mephitic Ooze gets +1/+0 for each artifact you control.

Whenever Mephitic Ooze deals combat damage to a creature, destroy that creature. The creature can't be regenerated.

, : Draw two cards.

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

Flying

Whenever you cast a kicked spell, scry 2.

Reach

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

When Mesmerizing Benthid enters the battlefield, 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.

Flying

Council's dilemma — When Messenger Jays enters the battlefield, starting with you, each player votes for feather or quill. Put a +1/+1 counter on Messenger Jays for each feather vote and draw a card for each quill vote. For each card drawn this way, discard a card.

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

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.)

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.

All Sliver creatures get +2/+2.

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Whenever a Human deals damage to you, destroy it.

Other non-Human creatures you control get +1/+1 and have undying. (When a creature with undying dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

This spell costs less to cast for each Spirit you control.

Flying

Whenever Millicent, Restless Revenant or another nontoken Spirit you control dies or deals combat damage to a player, create a 1/1 white Spirit creature token with flying.

When Mindclaw Shaman enters the battlefield, target opponent reveals their hand. You may cast an instant or sorcery spell from among those cards without paying its mana cost.

Trample

Whenever Mindleech Mass deals combat damage to a player, you may look at that player's hand. If you do, you may cast a spell from among those cards without paying its mana cost.