msem-instigator

Counter target spell. If a permanent spell is countered this way, you may aetherize it. (To aetherize, create a token that's a copy of it, then exile that token.)

[+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.”

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}.

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.

Menace
Foresight — Whenever you draw your second card each turn, search your library for a card, put it into your hand, then shuffle.

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.

When Master of Marble Row enters, choose one —
• Create a colorless Monument artifact token with “Creatures you control get +1/+1.”
• Create a white Cloister enchantment token with “When this enchantment enters, exile target nonland permanent an opponent controls until this enchantment leaves the battlefield.”

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast a noncreature spell, you may switch Master of Tranquility's power and toughness until end of turn.

[+1]: Untap up to two target creatures and/or lands.
[–2]: Choose a color. Draw cards equal to the number of creatures you control of the chosen color.
[–7]: Reveal the top ten cards of your library. Put all creature and land cards revealed this way onto the battlefield and the rest into your hand.

[+1]: Exile the top two cards of your library. You may play up to one card exiled this way this turn.
[–2]: Menna Al-Mejjat deals 3 damage to target creature. If that creature would die this turn, exile it instead.
[–6]: Draw cards equal to the number of cards in exile. Menna Al-Mejjat deals that much damage to any target.

Chosen one ({W}{U}{B}{R}{G}: Transform this permanent.)
[+2]: Exile the top two cards of your library. Until end of turn, you may play one card exiled with this permanent.
[+1]: Exile up to two cards from your hand, then draw that many cards.
[–3]: Menna, Servant to None deals 3 damage to up to one target player and up to one target creature or planeswalker.

Flying, haste
{X}{R}{R}, Exile an instant or sorcery card with mana value X from your graveyard: Return Merkurio's Familiar from your graveyard to the battlefield. It gets +X/+0 until end of turn.

Mettalia is all colors.
Mettalia has protection from each color among cards she's salvaged in exile.
When Mettalia enters, for each color, you may salvage a nonlegendary card of that color. (Exile one from your graveyard until this creature leaves the battlefield. Whenever this creature deals combat damage to a player, put a card it salvaged into your hand.)

Ferocious — Whenever a creature with power 4 or greater you control enters, Mieng, Who Dances With Dragons becomes a 4/4 Dragon creature with flying until end of turn.

Discard your hand, then draw three cards.
Mindstorm's Eye deals 3 damage to any target.

When Minister of Madness enters, create a 0/1 blue Weird creature token with flying.
{2}{U}, Sacrifice a creature: Search your library for an instant or sorcery card with mana value equal to 1 plus the sacrificed creature's mana value, exile that card, then shuffle. Then you may cast that card without paying its mana cost. Activate only as a sorcery.

Menace
At the beginning of your upkeep, if an opponent has more cards in hand than you, you draw a card and you lose 1 life.

Look at the top two cards of your library. You may put both of those cards into your graveyard or back on top of your library in any order.
Draw a card.

When Monstrous Hunter enters, destroy up to one target creature.
At the beginning of each end step, if a creature died this turn, you draw a card and you lose 1 life.

{T}: Add {C}.
{1}, {T}, Sacrifice Morphic Verge: Choose two different basic land types. Create a colorless land token that's the chosen types.

Mosecf, the Sunseeker's Path enters tapped.
Whenever a creature you control attacks, put a creation counter on Mosecf.
{T}, Remove ten creation counters from Mosecf and sacrifice it: Creatures you control get +2/+2 and gain vigilance until end of turn. Activate only as a sorcery.

Vigilance, reach, trample

At the beginning of combat on your turn, put a +1/+1 counter on target creature you control. If that creature has flying, transform Mounting Up.

{T}, Pay 1 life: Add {B}.
{T}, Pay 1 life, Sacrifice Murky Peat: Search your library for a Swamp card, put it onto the battlefield tapped, then shuffle.

Equipped creature gets +2/+2.
Concord — Whenever equipped creature attacks, if there are four or more card types among permanents you control, create a 3/3 red Shark enchantment creature token that's tapped and attacking. Exile that token at the beginning of the next end step.
Equip {1}