msem-instigator

Choose up to two target creatures. For each of those creatures, you may tap or untap it.
Scry 1. (To scry 1, look at the top card of your library. You may put that card on the bottom of your library.)

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Flash
Flying
When Mellan enters, exile up to one other target nonland permanent with mana value equal to or less than the number of creatures you control with flying until Mellan leaves the battlefield.

Put a +1/+1 counter on target creature you control. It can't be blocked this turn.
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

{1}, {T}: Surveil 2.
{U}, {T}, Discard a card: Look at the top card of your library. If it's a nonland card, you may cast it. (You still pay its costs)

({T}: Add {U} or {B}.)
Flooded Morass enters tapped unless you control a basic Island or a basic Swamp.

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Grave Revenant enters, target opponent loses life equal to the number of creature cards in your graveyard.

At the beginning of your upkeep, you lose 1 life, then audition for black. (Create a 1/1 Construct Actor creature token, a Cleric Role giving 2/2 and lifelink, or a Warlock Role giving 2/1 and flying. Roles replace older ones.)

Target creature gets -1/-1 until end of turn. Audition for black. (Create a 1/1 Construct Actor creature token, a Cleric Role giving 2/2 and lifelink, or a Warlock Role giving 2/1 and flying. Roles replace older ones.)

{1}{B}, Exile a creature or land card from your graveyard: Return Rotwood Whisper from your graveyard to the battlefield tapped.

As an additional cost to cast this spell, return a creature you control to its owner's hand.
Counter target spell.

Target opponent reveals their hand. You choose a nonland card from it. Exile that card. You lose 2 life.
Augmented — Then if you've spent {W}{U}{B}{R}{G} to cast spells this turn, you may cast that card without paying its mana cost.

Clocktower Hideout enters tapped.
When Clocktower Hideout enters, look at the top card of your library. You may put it into your graveyard.
{T}: Add {B} or {R}.

Reach
{1}: Untap Leapweb Lurker.

Slippery Capuchin can't be blocked.
Whenever Slippery Capuchin becomes the target of a spell or ability, you may change the target of that spell or ability.

At the beginning of your upkeep, discard a card and create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
When Cauldish Cavalier becomes renowned, you may pay 2 life. If you do, draw two cards.

Destroy each creature with power 3 or greater.

Haste
When Zipping Zapper enters, target creature gains haste and first strike until end of turn.

Whenever Culling Claw attacks, target creature gains winnow until end of turn. (Damage dealt to it also causes its controller to lose that much life.)

First strike
Redeye Commando's power is equal to twice the number of artifacts you control.
Redeye Commando attacks each turn if able.
Whenever Redeye Commando attacks, if its power is 6 or greater, it gains menace and trample until end of turn.

[+1]: Reveal the top card of your library and put it into your hand. Then if that card wasn't legendary, discard a card.
[–X]: Return target non-Reyhsia legendary permanent card with mana value X from your graveyard to the battlefield.
[–6]: Reyhsia, the Honorless deals 4 damage to each nonlegendary creature.

Enchant creature
When Feline Furor enters, it deals 2 damage to enchanted creature.
Enchanted creature gets +2/+0 and has menace.

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