msem-instigator

Destroy target artifact, enchantment, or planeswalker.
Orchestrate—{G}, Sacrifice a land. (You may exile this card from your hand anytime you could cast a sorcery for its orchestrate cost. When you next resolve a spell, you may cast this from exile without paying its mana cost.)

Whenever Malignant Afflicted perseveres, destroy target creature an opponent controls that dealt damage this turn. (A creature perseveres when it survives damage.)

{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.

Put any number of target creature cards from your graveyard on top of your library.
You draw two cards, and you lose 2 life.

Haste (This creature can attack and {T} as soon as it comes under your control.)
Double strike (This creature deals both first-strike and regular combat damage.)

Flying, vigilance
Exile a creature card from your graveyard: Maligned Scavenger gets +1/+1 until end of turn.

Whenever a non-Serf creature you control enters, create a 0/1 black Serf creature token.
Sacrifice a Serf: Target creature you control gets +0/+1 until end of turn.

Dominance — When Mammoth Crab enters, draw a card if you control the creature with the greatest power or tied for the greatest power.

Glitch—Discard a card. (Remove one [restriction] for each time you pay the glitch cost.)
Add {R} for each [Mountain] land you control, then exile the top three cards of your library. You may play [one of] those cards this turn.

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

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

Flying, vigilance
When Manafly enters, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

{T}: Add one mana of any color.

Pressure {G} (You may cast this spell for its pressure cost if there are seven or more cards in your graveyard.)
Deathtouch

When Manglehorn Hunter enters, draw a card and you lose 1 life.

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

Flash
Enspirit (As you cast this spell, you may exile a nonenchantment creature you control until this leaves the battlefield or fails to resolve. Reduce this spell's cost by the exiled card's mana value.)

Maniac Macaque attacks each combat if able.
Whenever Maniac Macaque becomes blocked by a creature, Maniac Macaque deals 1 damage to that creature.

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

Menace, haste
Whenever Manic River-Fishers attacks, you may search defending player's library for an instant or sorcery card that shares a name with a card in their graveyard and cast it without paying its mana cost. That player shuffles.

Glitch—Pay 3 life. (Remove one [restriction] for each time you pay the glitch cost.)
Create a 6/6 black Demon artifact creature token with flying, trample, [“This creature can't attack players with 10 or more life,”] [and “This creature can't block creatures with power 4 or less.”]

Add {R} and two mana of any one color.
When you next cast a spell this turn, Manifest Irrationality deals 3 damage to any target.

Flying
Whenever you attack, create two 1/1 white Human creature tokens that are tapped and attacking. Creatures you control get +1/+1 until end of turn.
Fleeting {2}{W}{W} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)

Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.
{5}{B}, Sacrifice Manipulations of the Div: It deals 4 damage to target player or battle and you gain 4 life. Activate only as a sorcery.

Enchant creature
When Mantle of the Returned enters, return target creature card from your graveyard to the battlefield. It's a Zombie in addition to its other types.
Enchanted creature gets +1/+1 for each Zombie you control.