msem-instigator

When Mettalia's Forward enters, you may salvage a card. (Exile one from your graveyard until this creature leaves the battlefield. Whenever this creature deals combat damage to a player, put a card it salvaged into your hand.)

(Activate each submodule once as a sorcery. When this enters, activate one submodule for free.)
{2}{U}: Imitate
Choose any number of target cards in graveyards. Their owners shuffle them into their libraries. Then you draw a card.
{2}{B}: Deceive
Surveil 5.
{1}{U}{B}: Obfuscate
Shadow Module gains “At the beginning of your upkeep, if there are four or more card types among cards in your graveyard, you may draw a card.”

Whenever another Zombie or Demon creature you control enters, 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.”)

Double strike
{1}{R}{W}: Target creature gains double strike until end of turn. Activate only if Bravery is in your graveyard.

{T}: Keepers of the Reach deals 1 damage to each opponent.
{2}{R}, {T}: Keepers of the Reach deals 3 damage to each opponent. Activate only if you control a permanent with mana value 5 or greater.

Haste
When Kragnoss, Rebellion Commander enters, create a 1/1 red Goblin creature token.
Whenever a Goblin you control attacks, Kragnoss, Rebellion Commander deals 1 damage to target creature defending player controls.

Menace
Whenever Issbarren Creeper deals combat damage to a player, draw a card, then discard a card.

Prismatic — Whenever you cast a multicolored spell, you may pay {1}. If you do, exile target nonland permanent, then return it to the battlefield tapped under its owner's control.

Surveil 2, then you draw a card and you lose 1 life. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
{2}{B}, Exile Corrupted Knowledge from your graveyard: Each opponent loses 2 life and you gain 2 life.

Flying
Harmony — Until the end of your next turn, you may cast target instant or sorcery card from your graveyard. If that card would be put into your graveyard, exile it instead.
When Aven Acoustimancer enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Until end of turn, if a source you don't control would deal damage to you or cause you to lose life, mill that many cards instead.

This spell costs {1} less to cast for each multicolored card in your graveyard.
Draw four cards.

({T}: Add {R} or {W}.)
Gnarled Henge enters tapped unless you control two or more basic lands.

Magma Spray deals 2 damage to target creature. If that creature would die this turn, exile it instead.

Flying
When Thief of Mortals deals combat damage to a player, as long as you control Thief of Mortals, gain control of target nonland permanent that player controls, and that permanent doesn't untap during its controller's untap step. Tap it.
At the beginning of each end step, if you control five or more permanents you don't own, you win the game.

Whenever Melodious Musician attacks, tap target creature an opponent controls.

({T}: Add {U} or {B}.)
Sodden Cavern enters tapped.

Primordial Slime can't be blocked by creatures with power 2 or less.
When Primordial Slime dies, you gain 5 life.
Foreshadow {5}{G}{G} (You may cast this spell for its foreshadow cost. If you do, also trigger its “dies” abilities when it enters.)

Flying
Whenever Angel of the Eclipse deals combat damage, it deals that much damage to each attacking and blocking creature.
Prevent all damage that would be dealt to Angel of the Eclipse by sources you control.

Other artifacts you control have ward {1}.
Overcast — Whenever you cast an artifact creature spell, if {C} was spent to cast it, it enters with an additional +1/+1 counter on it.

If one or more counters would be put on a creature you control, that many plus one of each of those kinds of counters are put on that creature instead.

Careless Violence deals 2 damage to each creature. If a creature dealt damage this way would die this turn, exile it instead.

Create two 1/1 red Elemental creature tokens.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, you may change the targets of up to one target spell or ability.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Destroy target creature you don't control with the greatest power.
II — Until your next turn, prevent all damage that would be dealt to you and planeswalkers you control.
III — Exile target card from a graveyard. You gain 2 life.

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)