msem-instigator

Assault {1}{B} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
Whenever a creature you control assaults, you may have target creature get -2/-2 until end of turn.

{T}, Sacrifice a permanent: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

If you would create a token, you may instead create a tapped 2/2 green Faerie Bard creature token.
Whenever one or more creature tokens you control deal combat damage to a player, that player sacrifices an artifact or enchantment.

Reach (This creature can block creatures with flying.)
Whenever a creature you control enters for the first time each turn, untap Skittering Swarm. It gets +1/+1 until end of turn.

When Diligent Analyst enters, you may put an progress counter on a Project you control.
Diligent Analyst gets +1/+1 as long as you control two or more enchantments.

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
At the beginning of your end step, you may untap another target permanent.

Creatures your opponents control get -2/-0 until end of turn.
Draw a card.

When Banner of Warfare enters, amass Soldiers 1. (Put a +1/+1 counter on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)
{1}, {T}: Add one mana of any color.

Nonbasic lands have “Whenever this land becomes tapped, you lose 1 life unless you sacrifice this land.”

Exile any number of target creatures you control. For each creature exiled this way, create a token that's a copy of it, except it's
a 4/4 white Angel Soldier with flying in addition to its other types.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — You may exile target nonland permanent. If you do, you lose 3 life.
III — Create a 7/7 white, black, and green Horror Knight creature token with trample and “Whenever this creature is dealt damage, you lose that much life.”
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Trample
{T}, Sacrifice another creature: You gain 3 life.
Whenever another creature you control dies, put a +1/+1 counter on Bloodbriar Archdruid.

[+1]: Draw a card. Each player loses 1 life.
[–2]: Create two 1/1 black Bat creature tokens with flying and lifelink.
[–3]: Target creature gets -13/-13 until end of turn. You control abilities of that creature that trigger this turn.

Until end of turn, you may play cards from your graveyard by paying 2 life in addition to those cards' costs.
If a card would be put into your graveyard from anywhere this turn, exile that card instead.

You may have Imitator of Success enter as a copy of any creature on the battlefield, except it has no mana cost and base power and toughness 1/1 if it's a token.
Successor {1}{U}{U} ({1}{U}{U}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost and base power and toughness 1/1. Succeed only as a sorcery.)

At the beginning of your upkeep, if you have more life than an opponent, create a 1/1 black Insect Spirit creature token with flying.
{3}{B}: Each opponent loses X life and you gain X life, where X is the number of Clerics you control.

When Eighth-Life Companion enters, put two +1/+1 counters on target creature you control.
Recite {1}{W} (You may cast this from your graveyard for its recite cost. If you do, exile it when it enters or if it would leave.)
Revive {2}{W}{W} ({2}{W}{W}, 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.)

Create a tapped Treasure token.
Memento {2}{B}{B} (You may cast this from your graveyard for {2}{B}{B}. If you do, put it onto the battlefield transformed after it resolves. Exile it if it would leave the battlefield or not resolve.)

Bloodprice {2}{B} (You may cast this card by sacrificing a creature and paying its bloodprice.)

At the beginning of each player's end step, that player sacrifices a permanent.

Trample, prowess
You may exert Wartorn Veteran as it attacks. When you do, double its power until end of turn. (An exerted creature won't untap during your next untap step.)

Concord — {T}: Tap target nonland permanent. Activate only if there are four or more card types among permanents you control.

Target creature gets +1/+0 and can't be blocked this turn.
Showcase {2}{U} (Then if you cast this for its showcase cost, create a 1/1 red Bard creature token that can't block and exile this. Whenever it attacks, you may cast a free copy of this.)

Whenever another creature or enchantment you control enters, you gain 1 life.
{3}{W}{W}, Pay 5 life: Castigated Sister becomes a 5/5 Angel Horror with flying. (This effect doesn't end at end of turn.)

Untap all creatures that attacked this turn. After this main phase, there is an additional combat phase followed by an additional main phase. For each planeswalker you control, you may activate its loyalty abilities an additional time this turn.