msem-instigator

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever one or more creatures you control survive damage, add a quest counter.
1 — You may put a creature card with mana value 2 or less from your hand onto the battlefield.
2 — Put two +1/+1 counters on target creature you control.
3 — Choose target creature you control. You draw cards equal to half that creature's power, rounded down.

Flash
Reach
Whenever Mattia enters or becomes tapped, put a +1/+1 counter on target creature you control.
{2}{G}, {T}: Target creature must be blocked this turn if able. Activate only as a sorcery.

When Mausoleum Rite enters, each player mills four cards.
{2}{B}, Exile a creature card from your graveyard: 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.”)

When Mausoleum Suffragan enters, create a white and black Aura enchantment token named Pale Shroud attached to target creature. The token has enchant creature and “Enchanted creature gets +1/+1 and has lifelink.”
Whenever an artifact or enchantment you control enters, each opponent loses 1 life.

When Maven of Fear enters, mill two cards.
Maven of Fear gets +2/+1 and has menace as long as six or more cards are in your graveyard.

Alpha (You may have this creature enter with a +1/+1 counter on it. If you do, it becomes alpha and can only attack alone.)

Enchant creature you control
Whenever enchanted creature attacks, mill three cards.
When enchanted creature leaves the battlefield, create an X/X green Spirit creature token, where X is equal to the number of card types among cards in your graveyard.

Gain control of target creature with power X or less.

Artifact vision (Whenever this or another artifact you control enters, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Mechanomind Researcher envisions an artifact card, put a +1/+1 counter on it.

Equipped creature gets +1/+1.
Whenever equipped creature becomes the target of a spell, you gain 3 life.
Equip {4}

Codex — Unraveling; Unraveling; Unrelenting; Unrelenting; Mindrip; Swipe Secrets. (As this enters, conjure its contents into a shuffled face-up additional library.)
Flash
When Mei's Collection enters, draw a card from its codex.

Return up to one target nonland permanent to its owner's hand. If you control a creature with flying, surveil 2.

Destroy target artifact.
Catalyze. (The next spell you cast this turn costs {1} less to cast.)

Choose one —
• Exile target player's graveyard.
• Target player sacrifices a creature.

Rapport — Whenever Memorial of Forgotten Heroes and at least one other creature you control become tapped, put a +1/+1 counter on one of those creatures.
{T}, Tap an untapped creature you control: Add one mana of any color.

Flash
When Mennin Pack enters, each opponent loses 1 life.
When Mennin Pack dies, each opponent discards a card.

Create X 1/1 black Goblin creature tokens. Gain control of target permanent with mana value X or less until end of turn. Untap it. It gains haste until end of turn.

Untap all nonland permanents you control.
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.)

Return target nonland permanent to its owner's hand. That player mills two cards.

Activated abilities you control cost up to {1} less to activate. This effect can't reduce the amount of mana an ability costs to activate to less than one mana.

Crew 3 (Tap any number of creatures you control with total power 3 or greater: This Vehicle becomes an artifact creature until end of turn.)

Deathtouch
Sacrifice a creature: Target player mills two cards.

Draw three cards, then put two cards from your hand on top of your library in any order.

Equipped creature gets +2/+0 and has haste.
Equip {2}

Whenever Merciless Bandit or another creature you control dies, each opponent loses 1 life and you gain 1 life.