msem-instigator

Trample
Enchantment spells and Aurashaper spells you cast cost {1} less to cast.
Whenever another enchantment you control enters, draw a card.

At the beginning of combat on your turn, if you cast an enchantment spell, an instant spell, and a sorcery spell this turn, create two 3/3 red Shark enchantment creature tokens. You may have any number of those tokens gain haste. If you do, sacrifice the tokens you chose at end of combat.

If you would create an Army token while Mehr's Unending Horde is in your graveyard, you may instead return Mehr's Unending Horde from your graveyard to the battlefield.
Counters remain on Mehr's Unending Horde as it moves to any zone other than a player's hand or library.

Whenever a player discards a card, you may draw a card and put a loyalty counter on Mei Liva, the Broken.
[0]: Target permanent's controller sacrifices it unless they discard two cards.
[–1]: Each opponent loses X life and you gain X life, where X is the number of cards in your hand.
[–3]: Target player chooses a card in their hand, then discards the rest.

[+1]: Search each player's graveyard, hand, and library for any number of cards with the same name as target nonbasic card in a graveyard and exile them. Then each player shuffles.
[–2]: Each player draws two cards, then each opponent exiles two cards at random from their hand.
[–5]: You may cast a card exiled with Mei Liva without paying its mana cost.

[+2]: Each opponent loses 2 life. Scry 2.
[–3]: Return target creature to its owner's hand. That player discards a card.
[–6]: You get an emblem with “Whenever a player discards a card, you may cast it without paying its mana cost.”

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.

[+1]: Draw a card unless an opponent discards a card.
[–3]: Gain control of target creature until the end of your next turn.
[–6]: Choose up to four cards in graveyards. You may play those cards without paying their mana costs.

Lifelink
Creatures can't be sacrificed.
{1}: Add {G}, {U}, or {R}. Spend this mana only to cast a Human spell.

Flash
Flying
When Mellan enters, exile up to one other target nonland permanent with mana value equal to or less than the number of creatures you control with flying until Mellan leaves the battlefield.

Melodae, the Favored can't be blocked by black creatures.
If Melodae would be destroyed, instead sacrifice a creature and Melodae gains indestructible until end of turn.

Enchant creature
When Melt the Chains enters, exile the top two cards of your library. Until the end of your next turn, you may play those cards.
Enchanted creature gets +3/+0.

(Choose only one work as a sorcery to add its ability.)
When Memorial Plaza enters, create two 1/1 colorless Spirit creature tokens with flying.
{2}{W}: The Warrior
At the beginning of combat on your turn, put a +1/+1 counter on target creature you control.
{1}{B}: Rhapsody in Black
At the beginning of your end step, you may sacrifice a creature. If you do, draw a card.

{X}, {T}: Search your library for a creature card with mana value X or less and no creature types noted by Memorial to Sir Jasper, put it onto the battlefield, then shuffle. Note that creature's creature types. Activate only as a sorcery.

When Memories Rewound enters, you may put target card from your graveyard on top of your library.
{1}: Put target card from your graveyard on the bottom of your library. Activate only once during each of your turns.

Enchant player
Whenever enchanted player casts a spell, they reveal cards from the top of their library until they reveal a card that shares a type with that spell, then puts all cards revealed this way into their graveyard.

When Memory Figment is put into your graveyard from your hand or library, you may exile it. If you do, for as long as it remains exiled, you may cast it. It costs {2} less to cast this way.

Enchant creature
Enchanted creature gets +1/+0.
Whenever enchanted creature attacks, target creature can't block this turn.

Whenever one or more creatures attack Menes, the Great Pyramid, create a tapped 2/3 black Mummy creature token.
[+1]: You get an emblem with “Black creatures you control get +1/+1.”
[–3]: Exile target creature card from a graveyard. Create a tapped token that's a copy of it except it's a black Mummy.

[+1]: Exile the top two cards of your library. You may play up to one card exiled this way this turn.
[–2]: Menna Al-Mejjat deals 3 damage to target creature. If that creature would die this turn, exile it instead.
[–6]: Draw cards equal to the number of cards in exile. Menna Al-Mejjat deals that much damage to any target.

Chosen one ({W}{U}{B}{R}{G}: Transform this permanent.)
[+2]: Exile the top two cards of your library. Until end of turn, you may play one card exiled with this permanent.
[+1]: Exile up to two cards from your hand, then draw that many cards.
[–3]: Menna, Servant to None deals 3 damage to up to one target player and up to one target creature or planeswalker.

Flash
Enchant instant or sorcery spell
Enchanted spell's text box is “This spell deals 3 damage to you.”
{4}{U}{U}{R}{R}: Return Mental Meltdown from your graveyard to the battlefield.

Enchant opponent
Whenever a creature enters under enchanted player's control, that creature gets -0/-2 until end of turn unless that player pays 2 life.

As Mercantile Accords enters, choose a number.
Whenever an opponent casts a spell with the chosen mana value, you draw a card and create a Treasure token.

Flying, vigilance