msem-instigator

When Humble Shepherd enters the battlefield, create a 0/1 white Sheep creature token.
{T}, Tap an untapped Sheep you control: Add one mana of any color.

Put a +1/+1 counter on target creature you control. Then that creature fights target creature you don't control. (Each deals damage equal to its power to the other.)

(As this Discovery enters and after your draw step, add a progress counter. Stop after you've discovered.)
I, II — Create a 3/3 green Beast creature token with defender.
Discovery — Creatures you control with defender can attack as though they didn't have defender.

Lifelink
When Hyctaleon's Vanguard enters the battlefield, look at the top six cards of your library. You may put a Soldier card with lesser mana value from among them onto the battlefield. Put the rest on the bottom of your library in a random order.
Other Soldiers you control get +1/+1.

Mill two cards, then you may return an instant or sorcery card from your graveyard to your hand.
Acquiesce (If you cast this spell from your hand, exile it as it resolves. When one or more creatures you control deal combat damage to an opponent, you may cast this card from exile without paying its mana cost.)

Vigilance
Imisti's Commando can't be blocked by creatures with lesser power.
Whenever Imisti's Commando deals combat damage to a player, draw a card.

Each opponent sacrifices a creature or planeswalker. If you own a foretold card in exile, you gain 4 life.

Whenever Imisti, Elven Insurgent attacks, mill two cards. When you do, you may return target land card from your graveyard to your hand.
{X}{B}{G}: If Imisti has no +1/+1 counters on it, put X +1/+1 counters on Imisti. Activate only as a sorcery.

Enchant creature
Enchanted creature gets +1/+1, has flying and lifelink, and is a legendary artifact in addition to its other types.

Flying
When Imperator Namuzzar enters the battlefield, search your library for an artifact or enchantment card, reveal it, put it into your hand, then shuffle.
Civilized — Lammasu you control get +2/+2 and have hexproof as long as you control an artifact, a creature, and an enchantment.

Draw a card.
Civilized — Instead draw two cards if you control an artifact, a creature, and an enchantment.

As Imperial Barracks enters the battlefield, you may reveal a Mountain or Plains card from your hand. If you don't, Imperial Barracks enters the battlefield tapped.
{T}: Add {R} or {W}.

All creatures get -2/-2 until end of turn.
Civilized — Instead only creatures your opponents control get -2/-2 until end of turn if you control an artifact, a creature, and an enchantment.

Exile target artifact or enchantment. Its controller creates a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Civilized — At the beginning of your upkeep, if you control an artifact, a creature, and an enchantment, you draw a card and you lose 1 life.

If a source an opponent controls would deal 2 or more damage to you, prevent 1 of that damage.
Civilized — Instead prevent all but 1 of that damage if you control an artifact, a creature, and an enchantment.

Draw a card. Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Create a tapped colorless Powercell artifact token with “{T}: Add {C}.” It doesn't untap during its controller's next untap step.

{T}: Add {C}.
{5}, {T}: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.

When Infamous Bilgecaptain enters the battlefield, forebode. (Create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.)
Other Pirates you control get +1/+1.
At the beginning of your end step, you may put a Pirate card with mana value less than or equal to the number of artifacts you control from your hand onto the battlefield.

Whenever Inishtu, Desert Healer enters the battlefield or attacks, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
At the beginning of your upkeep, if seven or more cards are in your graveyard, you may transform Inishtu.

Indestructible
{2}{B}, Exile two cards from your graveyard: Each opponent loses 2 life and you gain 2 life.

Sleight (You may cast this spell as though it had flash if you pay {1} more to cast it.)
Enchant creature you don't control
Embody (Enchanted creature is a copy of this card except for its types.)

Creatures you control get +2/+1 until end of turn.

When Into the Lion's Den enters the battlefield, target opponent reveals their hand. You choose a nonland card from it and exile that card until Into the Lion's Den leaves the battlefield.