msem-instigator

Create a 1/1 blue Illusion creature token with “This gets +1/+1 for each other Illusion you control.”
Acquiesce (If you cast this spell from your hand, exile it as it resolves. When one or more creatures you control deal combat damage to an opponent, you may cast this card from exile without paying its mana cost.)

Sacrifice Misleading Wisp:
Counter target spell unless its controller pays {1}.

Counter target noncreature spell with an odd mana value. (Zero is even.)

Glitch {2} (Remove one [restriction] for each time you pay the glitch cost.)
Create a 3/2 red creature token named Error with trample and haste. [Exile it at the beginning of the next end step.]

Foretell {3}{U}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
Draw a card. If this spell was foretold, draw three cards instead.

Flash (You may cast this spell any time you could cast an instant.)
When Mist Lurker enters, tap all creatures you don't control.

Hexproof
Mist-Valley Ancient enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

{1}{R}, Discard a card: Draw a card. Mist-Valley Minotaurs gets +2/+0 until end of turn.

Enchant creature
Enchanted creature has hexproof.
{U}: Return Mistcharm to its owner's hand.

Other Spirits you control get +1/+1.
Whenever Mistmourner or another Spirit you control enters, you may draw a card. If you do, discard a card.

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Whenever Mistress of Frost extorts a spell, you may tap target artifact or creature.

Dragon spells you cast cost {1} less to cast.
{1}{R}: Until end of turn, Miyoga Dragonsoul becomes a 2/2 red Dragon creature with flying and “{R}: Miyoga Dragonsoul gets +1/+0 until end of turn.” Activate only as a sorcery.

Flying, haste
Miyoga Firebird attacks each combat if able.
Whenever you cast your third instant or sorcery spell this turn, you may return Miyoga Firebird from your graveyard to the battlefield.

Defender
When Mnemonic Wall enters, you may return target instant or sorcery card from your graveyard to your hand.

Creatures you control with flying get +1/+1.
Whenever a creature you control with flying deals combat damage to a player, you may pay {U}. If you do, draw a card.

Modular Mercenary gets +1/+0 and has first strike as long as you control a creature with a +1/+1 counter on it.

First strike, haste
When Moeru Thunderers enters, if it's not a token, create a token that's a copy of it, except it has no mana cost.

Kicker {1}{G} (You may pay an additional {1}{G} as you cast this spell.)
When Mold Shambler enters, if it was kicked, destroy target noncreature permanent.

This spell costs {1} less to cast for each card type among cards in your graveyard.
Trample

Conjure into your hand a duplicate of target nontoken permanent you control or permanent card in your graveyard.
Exile Molecular Mimicry.

You may play Molten Basin from your graveyard as long as seven or more cards are in your graveyard.
Molten Basin enters tapped.
{T}: Add {B} or {R}.
Cycling {1}{B}{R} ({1}{B}{R}, Discard this card: Draw a card.)

Molten Mire enters tapped unless you control a basic land.
{T}: Add {B} or {R}.

Molten Ritual deals 3 damage to target creature. If that creature would die this turn, exile it instead.

Vigilance
{7}{G}: Molting Linnorm gets +5/+5 and gains trample until end of turn.

Target creature gets +1/+1 until end of turn.
Fabled {2}{R/W}{R/W} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that creature.)