msem-instigator

When March of the Unhallowed enters, mill three cards, then return a creature card with mana value 3 or less from your graveyard to the battlefield.
Whenever you attack with three or more creatures, each opponent loses 1 and you gain 1 life.

Hexproof from spells cast from a graveyard
If a creature you control would die and that creature was the target of an instant or sorcery spell this turn, you may put it on top of its owner's library instead.

The first creature spell you cast each turn costs {2} less to cast.
At the beginning of your upkeep, return a creature you control to its owner's hand. If you do, you draw cards and gain life equal to its power.

Choose one —
• Create a 2/2 green Wolf creature token. You may discard a card. If you do, draw a card.
• Destroy target artifact.
Flashback {3}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Equipped creature gets +2/+1.
Whenever a creature you control deals combat damage to a player or planeswalker, you may attach Mervin's Armor to it.
Equip {4}

When this enchantment enters, create a 1/1 white Peasant creature token.
{B/R}, Sacrifice a creature: Exile the top card of your library. You may play that card this turn.

Menace
{1}{B}, Exile another three cards from your graveyard: Return Determined Explorer from your graveyard to your hand.

Bustling Marketplace can't be sacrificed.
{T}: Add one mana of any type that a land you control could produce.
{0}: Bustling Marketplace's owner may draw a card. If they do, untap Bustling Marketplace and gain control of it until end of turn. Only your opponents may activate this ability and only once each turn during their turn.

Menace

Lifelink
Whenever another creature you control with a counter on it dies, return it to its owner's hand. If that creature was an Avatar, return it to the battlefield under your control instead.

Prevent all damage that would be dealt to each of up to three target permanents this turn.

When this creature enters, it seeks secrets or valor. (Give it that Oath Aura. Fulfill secrets by attacking with it and two or more other creatures to draw a card. Fulfill valor by dealing combat damage to a player to create a 2/1 white Soldier token.)
Arise {3}{B}{B} ({3}{B}{B}, Exile this from your graveyard as a sorcery: Create a black token copy of it that's also a Zombie and can't block.)

When Horn of Seasons enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equipped creature gets +3/+0.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

When Njel Crocodile enters, you may have it fight target creature. (Each deals damage equal to its power to the other.)

This creature has trample as long as there are four or more -1/-1 counters among creatures.
{3}{B}: Put a -1/-1 counter on target creature.

Whenever you cast a noncreature spell, up to one target artifact or non-Aura enchantment you control becomes a 3/3 creature in addition to its other types until end of turn.

{T}, Pay 1 life: Put a charge counter on Eternity Pendant.
If you would lose the game, instead your life total becomes equal to the number of charge counters on Eternity Pendant, then put Eternity Pendant on top of its owner's library.

Whenever you cast a spell, put a lore counter on Exhilarating Prescience.
At the beginning of your upkeep, exile the top X cards of your library, where X is the number of lore counters on Exhilarating Prescience. You may play those cards until your next turn.

Foretell {3}{U}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
Draw a card. If this spell was foretold, draw three cards instead.

Nightwatch Rallier enters with X +1/+1 counters on it.
Other artifact creatures you control get +1/+1 for each +1/+1 counter on Nightwatch Rallier.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — War's Sorrow deals 1 damage to any target.
III — Each player sacrifices another permanent. Put War's Sorrow on top of its owner's library unless a player has it deal 3 damage to them.

Whenever a creature you control deals combat damage to a player, if it has no +1/+1 counters on it, put a +1/+1 counter on it. You gain 1 life.

First strike
When Imperial Dragoon enters, target creature gets +2/+0 until end of turn.

Planeswalker spells you cast cost {1} less to cast for each storied permanent you control. (Enchantments and legendary permanents are storied.)

The “legend rule” doesn't apply to artifacts and enchantments you control.
Equipped creature gets +1/+1 for each artifact and/or enchantment you control.
Equip {2}