msem-instigator

I — Create a 1/1 green Insect creature token.
II — Create a 2/2 white Cat creature token.
III — Create a 3/3 red Ox creature token.
IV — Creatures you control gain vigilance and indestructible until end of turn.

Whenever you gain life for the first time each turn, create a 1/1 white Cleric creature token.

Whenever a creature you control perseveres, you draw a card and you lose 1 life. (A creature perseveres when it's dealt damage and doesn't die.)
{1}{B}: Deathmask Initiation deals 1 damage to target creature you control.

Menace
Whenever Dragon's Twisted Shadow attacks and isn't blocked, it gets +4/+0 until end of turn.

When Attuned Ancient enters, if you control a legendary creature, you may have Attuned Ancient deal damage equal to its power to target creature an opponent controls.

{G}, {T}: Target creature with power 4 or greater fights any number of target creatures you control.

Each opponent sacrifices an artifact.
Scry 1.
Coalesce {6}{R} (You may cast this from your graveyard for {6}{R}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on Champion of the Fae.

Create X 0/1 green Plant creature tokens, then distribute X +1/+1 counters among any number of creatures you control.

Harvest (You may tap any number of creatures you control as you cast this spell. If you do, reduce this spell's mana cost by their total power.)
{T}, Sacrifice a land: Search your library for a land card and put it onto the battlefield, then shuffle.

Hopeful Healer gets +1/+1 and has lifelink as long as you are glorious. (You are glorious as long as you have a glory counter.)

Vigilance
Other Knights and Soldiers you control get +1/+1.
{2}{B}, {T}, Sacrifice a Knight or Soldier: Destroy target creature or planeswalker. Activate only as a sorcery.

Whenever Mawdryk, Endrison Warden or another nontoken Elf creature you control enters, create a 1/1 green Elf Druid creature token.
{B}{G}, Sacrifice two Elves: Destroy target non-Elf creature.

Trample
Other Elementals you control get +1/+0 and have trample.

Discard a card: Search your library for a card with the same mana value as the discarded card, reveal it, put it into your hand, then shuffle. Activate only as a sorcery and only once each turn.

{R}: You may put a Rebel creature card from your hand onto the battlefield. That creature gains haste. Sacrifice the creature at the beginning of the next end step.

Enchantment creatures you control get +2/+2.

Flying
When Arbiter of Silence enters, exile all other creatures until Arbiter of Silence leaves the battlefield. (They return to the battlefield under their owners' control.)

Flash
When Devious Naiad enters, exchange control of it and target creature until end of turn. Untap that creature. It gains haste until end of turn.

Trample
Whenever Charging Cassowary deals combat damage to a player, you may cast a copy of an Adventure of a permanent you control.

Draw three cards, then discard two cards unless you discard a multicolored card.

Whenever you cast your first noncreature spell each turn, you may cast a creature spell with lesser mana value from your hand without paying its mana cost.
Whenever you attack with three or more creatures, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost.

When Kindled Vengeance enters, if you cast it, create seven 1/1 green Elf creature tokens.
Whenever you attack, Kindled Vengeance deals damage equal to the number of attacking creatures to target creature or planeswalker an opponent controls.

Menace
When Scion of Calamities enters, exile the top two cards of your library. Until the end of your next turn, you may play one of those cards.
Whenever a Mountain you control enters, you may aetherize Scion of Calamities. (To aetherize, create a token that's a copy of it, then exile that token.)