msem-instigator

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{3}{G}: Mill three cards. Target creature gets +X/+X and gains trample until end of turn, where X is the number of land cards in your graveyard.

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 and create a Masterpiece token of your choice.)
Whenever you cast a noncreature spell, create a 1/1 colorless Construct artifact creature token.

Create three 1/1 green Saproling creature tokens.

Whenever another enchantment you control enters, you may put a progress counter on Corporate War.
[progress 2-5] {W}{B}, Sacrifice a creature or enchantment: Destroy target creature or enchantment.
[progress 6+] Sacrifice a creature or enchantment: Destroy target permanent.
Sacrifice a creature or enchantment: Destroy target permanent.

{1}, Sacrifice Wayfarer's Amulet: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
{3}, Sacrifice Wayfarer's Amulet: Search your library for a riddle card, reveal it, put it into your hand, then shuffle.

Swirling Dragonfire deals damage to any target equal to the number of instant and sorcery cards in your graveyard.

Trample, haste
Skullbriar gets +1/+1 for each creature card in all graveyards.
{T}: Add {B} or {G}.
Skullbriar, Death's Mockery remains transformed as it moves to any zone other than a player's hand or library.

({T}: Add {B} or {G}.)
Whenever Nomad's Township becomes tapped, you lose 1 life unless you control two or more basic lands.

Double strike
Renown 2 (When this creature deals combat damage to a player, if it isn't renowned, put two +1/+1 counters on it and it becomes renowned.)

Whenever The First Idol 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.”)
Sacrifice three Idols: Return The First Idol from your graveyard your hand.

Whenever an opponent casts their first spell each turn, that player may pay {1}. If they don't, you may create a Treasure token and you may draw a card.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever you attack, add a quest counter.
1, 2 — Tap target creature an opponent controls.
3 — Create two 1/1 white Spirit creature tokens with flying.
​

Menace (This creature can't be blocked except by two or more creatures.)
Whenever a creature blocks, its controller loses 1 life.

(As an Encounter enters, choose an opponent to protect it. You and others can attack it. When defense counters are removed, create a 0/0 Army token if you don't control one, then put that many +1/+1 counters on a Army you control.)
When Crisis in Nizev enters, exile the top three cards of your library. Until the end of your next turn, you may play those cards.

Target creature gets +1/+1 for each creature you control and gains flying and vigilance until end of turn.

Whenever you cast a noncreature spell, you may pay {1}. If you do, scry 2. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
{1}{R}{G}: Warriors you control get +1/+0 and gain trample until end of turn.

Whenever The Dreamer enters or you play a card exiled with them, exile the top two cards of your library face down, then another face up.
You may play face up cards exiled with The Dreamer.
{T}, Sacrifice The Dreamer: Look at each face down card exiled with The Dreamer. You may cast one without paying its mana cost.

When Shaman of Burning Ashes enters, return target instant or sorcery card from your graveyard to your hand. When you do, each opponent loses X life, where X is that card's mana value.

Enchant creature you control
When Heliod's Benefaction enters, scry 2.
Enchanted creature gets +1/+1 and has lifelink.

Draw three cards, then reveal your hand.

Prowess
Whenever you cast a noncreature spell, create a 3/3 red Dragon creature token with flying.

This spell costs {2} less to cast if you've cast another spell this turn.
Enchant creature
When Tire Out enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Flash
Thorn-Touch Abomination enters with X +1/+1 counters on it.

Choose up to one nonland permanent. Return the rest to their owners' hands.