msem-instigator

Instant and sorcery spells you cast cost {1} less to cast.
Reprise and reverberate costs you activate cost up to {1} less.
Exile an instant or sorcery card from your graveyard: Add {U} or {R}. Spend this mana only to cast an instant or sorcery spell. Activate only once each turn.

When Lock Away enters, exile target nonland permanent an opponent controls until Lock Away leaves the battlefield.

Ward {2}
When Rewriter of Flesh enters, target creature you control becomes an enchantment and loses all other card types. (It still has its abilities, but it's no longer a creature.)

Activated abilities of sources you don't control can't be activated unless they're mana abilities.

Flying
Whenever Idol of the Dead God deals combat damage to a player, search your library for any number of creature cards named Idol of the Dead God, reveal them, put them into your hand, then shuffle.

Primal {5}{B}{G} (During your turn, you may cast this spell for {5}{B}{G} instead of playing a land.)
Whenever a permanent is put into a graveyard this turn, return it to the battlefield under your control at the beginning of the next end step. If you cast this spell for its primal cost, destroy target permanent.

Look at the top three cards of your library. Put one into your hand and the rest into your graveyard. You lose 1 life.

Return target creature card with power less than or equal to your fealty to Swamps from your graveyard to the battlefield. (Each Swamp you control counts towards your fealty to Swamps.)

Target creature's controller judges it. Then if they honored it, you gain control of that creature until end of turn. Untap it. It gains haste until end of turn. (That creature's controller honors it by putting a +1/+1 counter on it or condemns it by sacrificing it to draw a card.)

Art of war — At the beginning of your end step, if Kurayami Butcher dealt damage to an opponent, you may destroy target creature that was dealt damage this turn.

As long as there are three or more creature cards in your graveyard, Returned Minotaur gets +1/+1 and has menace.

Creatures your opponents control can't block alone. (They can block different creatures.)

All creatures get -2/-2 until end of turn.
Metamorph {1}{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.)

Aleud Beastmaster has frenzy X, where X is the number of unblocked attacking creatures you control. (Whenever it attacks and isn't blocked, it gets +X/+0 until end of turn.)

When Ruthless Conscript dies, arm up to two target creatures you control. (Create a colorless Equipment artifact token with “Equipped creature gets +1/+0” and equip {2}, then attach it to that creature.)

Counter target spell. Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Destroy target creature with power 4 or greater.

At the beginning of combat on your turn, choose one —
• Embodiment of Nature gains haste and hexproof until your next turn.
• Embodiment of Nature gains vigilance and indestructible until your next turn.
• Embodiment of Nature gets +2/+2 and gains trample until your next turn.

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.)

Equipped creature gets +2/+0.
Equipped creature has first strike as long as it's attacking.
Equip {2}

Untap target creature. It gets +2/+4 and gains reach until end of turn.

At the beginning of your upkeep, you may exile a card from your hand. If you do, draw a card.
Whenever equipped creature deals combat damage to a player, you may put a card exiled with Travel Pouch into its owner's hand.
Equip {1}

Ferocious — When Pack Familiar dies, if you control a creature with power 4 or greater, create two 2/2 green Wolf creature tokens.

Other Zombies you control get +1/+1.
Whenever Plague Herald or another Zombie enters under your control, target creature you control gains deathtouch until end of turn.

When Somnambulance enters, each player conjures a card named Fatigue and puts it on top of their library. (It's a colorless sorcery that costs {2} with “Draw a card.”)
Whenever a player casts a spell named Fatigue, you may draw a card. If you do, you lose 1 life.