msem-instigator

Search your library for an instant card or a card with flash, reveal it, put it into your hand, then shuffle.
Flashback {5}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Maniac Macaque attacks each combat if able.
Whenever Maniac Macaque becomes blocked by a creature, Maniac Macaque deals 1 damage to that creature.

Creatures blocking or blocked by Straw Officer have wither. (They deal damage to creatures in the form of -1/-1 counters.)

Harmony — Target creature gains flying until end of turn.
When Glamorous Aerialist enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Flying
When Cathedral Gargoyle dies, you gain 2 life and create a Weapon token. (It's an Equipment artifact with “Equipped creature gets +1/+1” and equip {2}.)
Foreshadow {4}{W} (You may cast this spell for its foreshadow cost. If you do, also trigger its “dies” abilities when it enters.)

{T}: Add one mana of any color.
{4}, {T}, Sacrifice Prototype Engine: Put four -1/-1 counters on target creature.

Resolute — Skerry Serpent must be blocked if able as long as its power is greater than its base power.

Put up to X target noncreature, nonland permanents on top of their owners' libraries in any order.
You gain 6 life.

When Duskling Stalker dies, if it didn't have any counters on it, return it to the battlefield with your choice of a deathtouch, lifelink, or +1/+1 counter on it.

If an effect would cause an opponent to discard one or more cards while they have fewer than that many cards in hand, they lose life equal to three times the difference instead of discarding the excess cards.

Whenever one or more creatures you control deal combat damage to a player, you may discard a card. If you do, draw a card.
{2}{R}, {T}, Exile two cards from your graveyard: Sarrutu Flamebinder deals 2 damage to any target.

Reveal the top four cards of your library. You may put a permanent card revealed this way with mana value less than the greatest mana value among permanents you control onto the battlefield. Put the rest on the bottom of your library in a random order.

As an additional cost to cast this spell, tap an untapped artifact you control.
Target player discards two cards.

You may put a card you own from outside the game into your hand. Add {B}{B}. You may cast only one more spell this turn. Exile Power From Beyond.

When Loyal Retriever dies, search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.
Foreshadow {5}{W} (You may cast this spell for its foreshadow cost. If you do, also trigger its “dies” abilities when it enters.)

Flying
When Qi-Long Rainbringer enters, return up to one other target creature to its owner's hand.

Creatures you control get +1/+1 until end of turn. Merfolk you control get an additional +1/+1 until end of turn.

Bloodcrazed Acolyte enters with a +1/+1 counter on it for each player who lost life this turn.

Scathing Review deals 2 damage to target creature. If you control an artifact, Scathing Review deals 2 damage to that creature's controller.

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)
When Arbiter of Shal'Iv enters, adjudicate. (Create a white enchantment Aura token with enchant creature and “Sacrifice this token: Untap enchanted creature” attached to target creature.)

When Drifting Warden enters, exile another target creature until Drifting Warden leaves the battlefield.
{3}{W}: Exile Drifting Warden. Return it to the battlefield under its owner's control at the beginning of the end step.

Creatures you control get +2/+2 and gain trample until end of turn. If you cast this spell from exile, creatures you control get an additional +2/+2 until end of turn.
Prophecy {2}{G}{G} (Once each turn, you may exile a card with prophecy as you reveal it. When you do, you may cast it for its prophecy cost as long as it's exiled.)

{2}{R}, Tap an untapped creature or Karina planeswalker you control: Copy target instant or sorcery spell, activated ability, or triggered ability. You may choose new targets for the copy. Activate this ability only once each turn.

{T}, Sacrifice Serene Trail: Search your library for a Forest or Plains card and put it onto the battlefield tapped, then shuffle.

({T}: Add {U} or {R}.)
Roaring Cascade enters tapped.