msem-instigator

Marrowskitter can't block and can't be blocked.
{3}{B}{B}: Return Marrowskitter from your graveyard to the battlefield. Create a token that's a copy of it.

Renown 1
When Marshal Jin Guiying becomes renowned, you may search your library for an artifact or enchantment card, reveal it, put it into your hand, then shuffle.

Whenever Marshback Knights becomes the target of a spell or ability an opponent controls, counter it unless they pay {3}.
{1}{U}: Marshback Knights gains flying until end of turn.

When Marshcroaker Coaching enters, create three 1/1 blue Frog creature tokens.
Frogs you control have “{T}: Target creature gains flying until end of turn.”

Whenever another creature you control dies, put a +1/+1 counter on Marshy Marauder.
When Marshy Marauder dies, create a 1/1 green Insect creature token for each counter on it.

First strike
Whenever Martial Maestro attacks, other attacking creatures you control get +1/+0 until end of turn.

Choose two —
• Until end of turn if an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
• Create three 1/1 green Snake creature tokens.
• Create a 2/2 blue Bird creature token with flying.
• Create a 3/3 red Manticore creature token with haste.

Double the number of each kind of counter on target creature you control.

Discard your hand, then draw two cards for each land card discarded this way. For each opponent, Marzen's Frenzy deals damage to that player or a planeswalker they control equal to twice the number of instant or sorcery cards discarded this way.

Lifelink
If you would gain life, you may put that many +1/+1 counters on another creature you control instead.

First strike
When Masha Ritualist enters or whenever you cast a spell, if {B}{G} was spent to cast it, return target creature card with mana value 3 or less from a graveyard to the battlefield under your control. Put a +1/+1 counter on Masha Ritualist.

Whenever Masha's Vanguard deals damage to a player, you may put a creature card with mana value X or less from your hand onto the battlefield, where X is the amount of damage dealt this way.

You have hexproof.
Whenever a creature deals combat damage to you or a planeswalker you control, Mask of Shikai deals 1 damage to that creature.

Masked Impersonator can't be blocked.
Art of war — At the beginning of your end step, if Masked Impersonator dealt damage to an opponent this turn, you may have it become a copy of target creature you control except it has this ability.

Menace
Whenever Masoh enters or attacks, each opponent that has more than four cards in hand discards cards equal to the difference. Then if you have fewer than four cards in hand, draw cards equal to the difference.

Whenever another creature enters, Masquerading Bohemian becomes a copy of that creature except it's a Noble in addition to its other types and it has this ability.

Create two tokens that are copies of target creature you control, except the tokens aren't legendary if the creature is legendary. Those creatures gain haste until end of turn.

Whenever a permanent you control leaves the battlefield, discard a card, then draw a card.
{1}{R}, Sacrifice a permanent: Mass Pandemonium deals 1 damage to any target.

Flash
When Master Echomage enters, you may cast target instant or sorcery card from your graveyard with mana value X or less without paying its mana cost, where X is the number of Wizards you control. Exile that card instead of putting it into your graveyard as it resolves.

When Master Negotiator enters, you may gain control of target nonland permanent an opponent controls with mana value 2 or less. If you do, its controller may draw a card. Otherwise, you draw a card.

Creatures you control attacking cause abilities of that creature to trigger as though it entered.
{2}{R}{W}: Target creature gains vigilance and haste until end of turn. After this main phase, there is an additional combat phase followed by an additional main phase.

Other creatures you control get +0/+1.

Flash
When Master of Disorientation enters, you may choose new targets for target instant or sorcery spell. Then proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Instant and sorcery spells you cast cost {1} less to cast.
{U}, {T}, Exile three instant and/or sorcery cards from your graveyard: Draw a card.