msem-instigator

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever a land you control enters, add a quest counter.
Create a 1/1 Scout creature token that's all colors.
Creatures you control get +2/+1 until end of turn.
Creatures you control get +1/+1 until end of turn.

Choose target spell. If it's an instant, a sorcery, or you cast this spell from exile, copy it. You may choose new targets for the copy.
Prophecy {2}{U}{U} (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.)

{3}{U}, Reveal this card from your hand, Return an unblocked attacking creature you control to its owner's hand: Put Phasewalker Rake from your hand onto the battlefield tapped and attacking. If you returned a Pirate or Rogue this way, draw a card.

Create X 1/1 white Nymph creature tokens. Until end of turn, creatures you control gain protection from each color among permanents you controlled as you cast United Force.

I, II — Whenever a creature you control attacks alone this turn, put a +1/+1 counter on it.
III — Whenever a creature you control attacks alone this turn, it gains double strike and lifelink until end of turn.

Whenever you cast an instant or sorcery spell, upgrade Error Exploiter. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Flying
• Hexproof

Whenever Adept Lieutenant attacks, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
{1}, Sacrifice an Idol: Put a +1/+1 counter on Adept Lieutenant.

Create four 3/3 green Elemental creature tokens.
Flashback {7}{G}{G}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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

Vanguard — Whenever a creature you control attacks alone, target creature can't block this turn.

The Unshakable Kian enters with three wish counters on him.
Remove a wish counter from Kian: Choose one. Activate only as a sorcery and only once each turn.
• Kian gains hexproof and trample until your next turn.
• Tap up to three target nonland permanents and put a stun counter on each of them.
• If you have fewer than four cards in hand, draw cards equal to the difference.

Flying
You may reveal the second card you draw each turn as you draw it. Whenever you reveal a nonland card this way, copy that card. You may cast the copy. If you don't, Brutal Director deals 2 damage to any target. (You still pay the spell's cost.)

{T}: Add {C}.
{1}, {T}, Return Collapsing Ground to its owner's hand: Add one mana of any color.

Menace (This creature can't be blocked except by two or more creatures.)
Whenever Weedy Whackers attacks, create a 1/1 green Insect creature token that's tapped and attacking.

Whenever a nontoken creature dies, you may exile that card. If you do, return each other card exiled with Tome of the Lidless Gaze to its owner's graveyard.
At the beginning of your upkeep, if you control no Eyes, create a token that's a copy of a card exiled with Tome of the Lidless Gaze except it's a 2/2 Eye Horror with flying in addition to its other types.

Target opponent reveals their hand. You choose a nonland card from it. That player discards that card.
Create a Function token with “Draw a card if a player discarded a card this turn.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

When Contagious Host dies, each player loses 1 life.
Revive {2}{B} ({2}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Whenever one or more creatures you control deal damage to a player, put a charge counter on Lake of Rage.
{T}: Add {C}.
{T}, Remove a charge counter from Lake of Rage: Add one mana of any color.

Target player reveals their hand. You choose a nonland card from it. That player discards that card. Create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

You may exert Migrating Herd as it attacks. When you do, sacrifice a land and draw a card. (An exerted creature won't untap during your next untap step.)

Whenever another creature you control dies, put a +1/+1 counter on Deathfeeder.
Sacrifice Deathfeeder: Target creature gets +X/+X until end of turn, where X is Deathfeeder's power.

I, II — Scry 1. You get a research counter.
III, Discovery — Eureka! (At the beginning of each end step, you get a research counter if you cast a spell this turn. Then if you have eight or more research counters, remove them all and create a Masterpiece token of your choice.)

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
Whenever a Demon you control enters, put a +1/+1 counter on Tzelin.
{2}{B}: Sacrifice Tzelin. If you do, each opponent loses life equal to Tzelin's power. If you're in a renaissance, also draw that many cards.

Reach
{1}: Untap Leapweb Lurker.

Enchantments you control have hexproof.
Wira Inti, Skyfather can't attack or block unless you control five or more enchantments.
At the beginning of combat on your turn, up to two other target enchantments you control each become a creature in addition to their other types and have flying, vigilance, and base power and toughness 4/4.