msem-instigator

{T}: Add one mana of color.
{3}{G}, {T}: Audition for green. Activate only as a sorcery. (Create a 1/1 Construct Actor creature token, a Scout Role giving 2/3 and vigilance, or a Warrior Role giving 3/2 and trample. Roles replace older ones.)

Artifact spells you cast cost {1} less to cast.
{2}, Sacrifice an artifact: Target creature gains deathtouch until end of turn.

When Mettalia's Forward enters, you may salvage a card. (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.)

Mianju enters with your choice of a menace or +1/+1 counter on them.
Whenever two or more creatures in Mianju's pack attack, mill three cards, then return a creature card from your graveyard to your hand. (Two or more creatures you control with equal power are in a pack.)

When Miasma Spewer enters, you may sacrifice a permanent. When you do, Miasma Spewer deals 1 damage to each opponent and each creature and planeswalker they control.

Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.
{2}{B}: Create a 1/1 black Rat creature token with “This creature can't block.” Activate only if there are five or more creature cards in your graveyard.

Enchant opponent
Whenever Middleware or another Curse becomes attached to enchanted player, exile the top card of that player's library face down. For as long as that card remains exiled, you may look at it and you may play it. Mana of any type can be spent to cast that spell.

Once each turn, when you activate a nonmana ability, you may create a tapped 1/1 white Spirit creature token with flying.
{4}{W}{U}: You gain 1 life and draw a card.

Target opponent discards two cards, then sacrifices a creature.

({T}: Add {B}.)
As Midnight Gate enters, you may pay 1 life. If you don't, Midnight Gate enters tapped.
Basic lands you control have “{T}: Add {B}.”

Flash

Whenever you cast a spell from exile, put two +1/+1 counters on Midnight Vagrant. It gains menace until end of turn.
{1}{B}{B}: Exile the top card of target opponent's library. You may play that card during any turn you attacked with a Rogue, and you may spend mana as though it were mana of any color to cast it. Activate only as a sorcery.

Each player loses 2 life, discards two cards, sacrifices two creatures, then sacrifices two lands.

Haste
{R}, {T}: Miede-District Enforcer deals 2 damage to target creature that entered this turn or player that cast a creature spell this turn.
Paranoia {1}{R} (You may cast this spell for its paranoia cost when a permanent you control leaves the battlefield.)

Until end of turn, target creature gains double strike and damage dealt by it can't be prevented.
Fuse (You may cast one or both halves of this card from your hand.)

Flash
When Mighty Beetle enters, you may put two +1/+1 counters on target creature you control.

Search your library for a basic Forest or Plains card, put that card onto the battlefield tapped, then shuffle.
{3}{W}, Exile Migration Range from your graveyard: Create two 1/1 green and white Elk Spirit creature tokens. Activate only as a sorcery.

Whenever you gain life, Militant Youth gets +1/+1 until end of turn.

When Militant's Standard enters, draw a card if you control a Merfolk.
Equipped creature gets +2/+1.
Equip {2}

At the beginning of your upkeep, you gain 1 life for each creature you control.
{3}{W}: Create a 1/1 white Soldier creature token. Activate only if you have the highest life total among all players.

When Militia Commander enters, create a 1/1 white Peasant creature token.
Other Citizens and Peasants you control get +1/+1.

Lifelink
When Milunda, Prairie Prince enters, each opponent loses life equal to the number of storied permanents you control and you gain that much life. (Enchantments and legendary permanents are storied.)

Enchant player
Enchanted player's maximum hand size is reduced by two.

Whenever a source you control deals noncombat damage to a player, put a +1/+1 counter on Mindblaze Pyromancer.