msem-instigator

When Malicious Growth enters the battlefield and at the beginning of your upkeep, put two +1/+1 counters on target land you control.
{1}{G}: Target land you control becomes a 0/0 Elemental creature with haste and vigilance until end of turn. It's still a land.

{2}: Exile up to two target cards in a single graveyard. If two creature cards were exiled this way, create a 1/1 blue Elemental creature token with flying.

When Mana Rose enters the battlefield, you gain 2 life and scry 2.
{1}, {T}: Add one mana of any color.

Manaflux Battery enters the battlefield tapped.
{T}: Add {C}{C}.
{2}, {T}: Untap each other artifact you control.

Menace
Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)

Marin Polgek, Academy Heiress has hexproof as long as you control three or more enchantments.
{1}{W/U}{W/U}: Create a token that's a copy of target enchantment you control.

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.

Marshy Vista enters the battlefield tapped.
{T}: Add {B} or {R}.
{1}, {T}: Add one mana of any color.

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

Whenever an artifact enters the battlefield under your control, Master of Munitions deals 1 damage to each opponent.

Choose X. If X is 5 or greater, you may choose the same mode more than once.
• Each opponent discards a card.
• Each opponent sacrifices a creature.
• Each opponent loses 2 life.
• You draw a card and you lose 1 life.

When Matron of Machines dies, put a +1/+1 counter on up to one target creature.
{3}{W}, Exile Matron of Machines from your graveyard: Create two 1/1 colorless Construct artifact creature tokens. Activate only as a sorcery.

When Meadow Songstress enters the battlefield, conjure three cards named Meadow Songstress and shuffle them into your main library.
Whenever a nontoken creature enters the battlefield under your control, if it shares a name with one or more other creatures you control, draw a card.

Gain control of target creature with power X or less.

Choose one —
• Exile target player's graveyard.
• Target player sacrifices a creature.

Whenever Memory of Fatalism dies or you cast a noncreature spell, each opponent loses 2 life and you gain 2 life.
{4}: Put Memory of Fatalism from your graveyard on top of your library.

Other Elementals you control get +2/+2.
Whenever one or more Elementals you control attack, tap up to one target creature you don't control.

Menace

Choose one —
• Meteor Fall deals 4 damage to each creature and each planeswalker.
• Meteor Fall deals 8 damage to target creature or planeswalker.

When Meteor Harbinger enters the battlefield, choose one —
• Meteor Harbinger deals 2 damage to each creature.
• Each player sacrifices two lands.
• Meteor Harbinger deals 2 damage to each of two target players or planeswalkers.

Whenever a land enters the battlefield under your control, crystallize.
{10}: Shuffle any number of other permanents you control into their owner's library. Mill that many cards. Put all permanents cards milled this way onto the battlefield. Activate only during your turn and only once each turn.

Creatures with power greater than the number of cards in their controller's hand can't attack.

When Mineral Expert enters the battlefield, surveil 1. When you do, you may return target instant or sorcery card from your graveyard to your hand. (Look at the top card of your library. You may put that card into your graveyard.)

Flying
When Mineral Retriever enters the battlefield, create a Treasure token.

When Mining Rover Manager enters the battlefield, create a 1/1 colorless Servo artifact creature token.