msem-instigator

Search your library for an Equipment card, reveal it, put it into your hand, then shuffle. (Then exile this card. You may cast the creature later from exile.)

[+1]: Scry 2. Whenever one or more creatures you control deal combat damage to a player this turn, draw a card.
[–2]: Create a token that's a copy of target creature you control, except the token is 4/4 and has vigilance.
[–7]: You get an emblem with “At the beginning of your draw step, draw two additional cards” and “Creatures you control get +1/+1 for each card you've drawn this turn.”

{T}, Discard a card: Draw a card.
{1}, {T}, Discard a card: Scry 2, then draw a card.
{4}, {T}, Discard a card: Search your library for a card, put it into your hand, then shuffle.

Return target creature card with mana value 5 or less from your graveyard to the battlefield.
Metamorph {B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up and cast it at any time for its metamorph cost.)

Haste
Whenever Malformed Mongrel deals combat damage to a player, discard a card.

{T}: Add one mana of any color.

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

For each of up to X target creature cards in your graveyard, create a token that's a copy of it. Exile the tokens at the beginning of the end step.

{T}: Add {C}.
{T}, Pay 1 life: Add one mana of any color. Spend this mana only to cast a legendary spell or activate an ability of a legendary permanent.
{3}, {T}, Sacrifice Many-Voiced Tower: Search your library for a legendary card, reveal it, put it into your hand, then shuffle. Activate only if you control five or more differently named lands.

When Marauding Goliath becomes blocked by a creature with power 1 or less, sacrifice it at end of combat.

Improve {1}{W} ({1}{W}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Prevent all combat damage that would be dealt to attacking embattled creatures you control. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

[+1]: Exile up to one target tapped creature.
[–2]: Create a 4/4 white Angel creature token with flying.
[–3]: Destroy all creatures. You gain 1 life for each creature destroyed this way.
[–7]: You get an emblem with “At the beginning of each end step, you gain life equal to twice the life you've lost this turn.”

Deception {2}{U}{U} ({2}{U}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
As long as it's your turn, Marilye is a 3/2 Elf Rogue creature with hexproof and indestructible.
[+1]: Tap target permanent. It doesn't untap during its controller's next untap step.
[–2]: Exile the top five cards of target opponent's library. You may cast any number of cards exiled this way with total mana value less than or equal to the amount of damage dealt to them this turn without paying their mana costs.

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.

You may return a land you control to its owner's hand rather than pay this spell's mana cost.
Marinton-Ravengulch Line enters tapped.
{T}: Add {B}.

Whenever Maritime Thug becomes tapped, it deals 1 damage to each opponent.

{T}: Add one mana of any color.
{1}, {T}: You get a glory counter. (You lose glory counters before life. A player with ten or more glory counters wins the game.)

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.

Exile any number of target creatures. For each creature exiled this way, its controller creates a 3/2 green Crocodile creature token with trample.

{1}: Look at the top card of your library.
{T}, Sacrifice Marked Coin: You may shuffle your library. Draw a card.

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

At the beginning of your upkeep, exile the top card of your library. Masahita, Bloodtongue deals damage to you equal to that card's mana value. Until end of turn, you may play that card.

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{1}, {T}: Look at the top card of your library. You may put the card back or into your graveyard.

{T}: Add {C}.
Whenever you tap Masamori Initiate for mana, you may mill a card.

When Mass Orator enters, if it isn't a token, populate. (Create a token that's a copy of a creature token you control.)
Creature tokens you control get +1/+1.