msem-instigator

Once each turn, when Eruq, the Flamebearer enters or you attack with one or more Horrors, you may have Eruq deal 2 damage to each opponent. Then if Eruq isn't a token, gain control of target creature an opponent controls until end of turn. Tap it. It's attacking its controller.
{2}{R}{R}, Discard Eruq: Create a token that's a copy of Eruq, the Flamebearer, except it's 4/4 and isn't legendary. Activate only as a sorcery.

{2}{G}: Look at the top three cards of your library. You may reveal a creature or Revelation card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Counter target spell unless its controller pays {3}. Its controller mills three cards.

Menace (This creature can't be blocked except by two or more creatures.)
Whenever another creature dies, you may salvage a creature 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.)

Flash
Flying
At the beginning of each end step, if two or more spells were cast this turn, you may draw a card. If you do, discard a card.

Civilized — When Marble Row Healer enters, if you control an artifact, a creature, and an enchantment, you gain 4 life.

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
Target creature you control gets +1/+0 until end of turn if you're in a renaissance. Then that creature deals damage equal to its power to target creature you don't control.

Haste
Whenever another creature you control dies, you may return an Aura that was attached to that creature to the battlefield attached to Kafyabari Enforcer.

Vigilance
Whenever Keeper of the Bloodline and at least two other creatures attack, creatures you control get +1/+1 until end of turn.

({T}: Add {U} or {R}.)
Boiling Ridge enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Flying
When Windrider Elemental enters, target creature gains flying until end of turn.

Equipped creature is a Flagbearer in addition to its other types.
While an opponent is choosing targets as part of casting a spell they control or activating an ability they control, that player must choose at least one Flagbearer on the battlefield if able.
Equip {5}

[+1]: Create two 1/1 red Satyr creature tokens.
[–1]: Until your next turn, target creature has base power and toughness X/X, where X is the number of permanents you control.
[–8]: Reveal the top card of your library. If it's a permanent card, you may put it onto the battlefield, then repeat this process.

Look at the top four cards of your library. Put two of them into your hand and the rest into your graveyard.
{4}{U}{B}, Exile four other cards from your graveyard: Return Fourth Eye Dealings from your graveyard to your hand.

Whenever an Actor you control becomes untapped, you may discard a card. If you do, draw a card.

When Expedition Outfitter enters, create a 1/1 colorless Servo artifact creature token.
At the beginning of each end step, if an artifact was put into your graveyard from the battlefield this turn, Expedition Outfitter deals 1 damage to each opponent.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever you attack, add a quest counter.
1 — Create a 0/1 white Human creature token named Lost Child.
2 — Scry 2.
3 — Exile a token you control named Lost Child. If you do, create two 1/1 white Soldier creature tokens and you gain 4 life.

Creature spells you cast cost {1} less to cast.
Whenever you attack, target attacking creature you control gets +1/+1 until end of turn. If it's legendary, put a +1/+1 counter on it instead.

Marshy Vista enters tapped.
{T}: Add {B} or {R}.
{1}, {T}: Add one mana of any color.

Whenever you put one or more -1/-1 counters on a creature, put that many charge counters on Cycle of Scars.
Remove three charge counters from Cycle of Scars: Copy target instant or sorcery spell you control. You may choose new targets for the copy.

Exile target enchantment or Equipment.

Trample
Whenever you cast a noncreature spell, crystallize. If you create a Treasure this way, Heartforge Savant deals 1 damage to you for each Treasure you've created this turn. (Put a +1/+1 counter on a creature you control or create a Treasure.)

Melodae, the Favored can't be blocked by black creatures.
If Melodae would be destroyed, instead sacrifice a creature and Melodae gains indestructible until end of turn.

Scry 1. Draw a card. Scry 1.

At the beginning of your declare attackers step, create a 0/1 white Cat creature token that's tapped and attacking. Exile that token at the beginning of the next end step.