msem-instigator

When Viking Greataxe enters, attach it to target creature you control.
Equipped creature gets +2/+1.
Equip {3}

Target player sacrifices a creature.
Create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
Whenever a creature you control enters, each opponent loses 1 life.
I, II — Create a 1/1 black Actor creature token with lifelink.
III — Each opponent loses life equal to the number of tokens you control. You gain life equal to the life lost this way.

Whenever one or more creatures die for the first time each turn, you draw a card and you lose 1 life.
Whenever you cast a black noncreature spell, Villainy deals 2 damage to any target and you gain 2 life.

Target opponent exiles two cards from their hand. If that player is cursed, they lose 3 life.

All creatures get -3/-3 until end of turn.

Destroy target nontoken artifact. 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.”)

Destroy target creature or planeswalker. Each player loses life equal to that permanent's mana value.

As an additional cost to cast this spell, sacrifice an artifact or creature.
Create three 1/1 red Construct creature tokens.

This spell costs {1} less to cast for each creature that attacked this turn.
Violent Offensive deals 4 damage to any target.

Enchant creature
Whenever enchanted creature becomes tapped, Violent Repercussions deals 3 damage to that creature's controller.

Reverberate {3}{U} (When you cast this spell, copy it if you paid its reverberate cost.)
If Violent Spasm is reverberated, creatures you control gain flying until end of turn. Violent Spasm deals 1 damage to each creature without flying.

If two or more creatures an opponent controls are attacking, you may pay {B} rather than this spell's mana cost.
Create a 1/1 black Snake creature token with deathtouch. It gains first strike until end of turn.

Target creature gains deathtouch until end of turn.
Draw a card.

When Viridian Townships enters, create two Idol tokens. (They're artifacts with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
{2}, Sacrifice an Idol: Draw a card.
{2}, Sacrifice an Idol: You gain 3 life.

{2}, {T}, Sacrifice Virtual Terrain: Search your library for a land card, put it onto the battlefield tapped, then shuffle.

Virtuoso's Parlor enters tapped.
When Virtuoso's Parlor enters, look at the top card of your library. You may put it into your graveyard.
{T}: Add {W} or {B}.

Draw two cards, then discard two cards.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

Once each turn, you may activate an additional loyalty ability of a planeswalker you control.
[+1]: You gain 1 life for each loyalty ability you've activated this turn. Scry 1.
[0]: Put a +1/+1 counter on target creature. It can't attack or block until your next turn.
[–3]: Exile target creature with power 4 or greater.

Target creature you control deals damage equal to its power to target creature you don't control.

Target player draws X cards and loses X life.

Enchant creature
Enchanted creature blocks each combat if able.
Whenever enchanted creature attacks, it loses flying until end of turn.

Archive 13 (As this enters, shuffle the top thirteen cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
At the beginning of your upkeep, you lose half your life, rounded up, and you draw half of the cards from the archived library, rounded up.

You may cast up to two target instant and/or sorcery cards from your graveyard this turn. If a spell cast this way would be put into your graveyard, exile it instead.

Whenever you attack, create a white Equipment artifact token with “Equipped creature gets +1/+1” and equip {1}. Attach it to an attacking creature you control.
At the beginning of your end step, untap each embattled creature you control. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)