msem-instigator

When Maaru, Tomb Guardian enters, create three Treasure tokens.
Each Treasure you control is an artifact creature with power and toughness each equal to the number of Treasures you control.

[+1]: Create a tapped colorless land token named Far-Off Lands with “{T}: Add one mana of any color.”
[–1]: Choose a color. Untap all lands you control that could produce that color.
[–6]: Draw a card for each differently named land you control.

[+1]: Return a land you control to its owner's hand. Create a tapped colorless land token named Far-Off Lands with “{T}: Add one mana of any color.”
[–1]: Discard a card. Return to your hand a card from your graveyard that shares a color with that card or a color of mana it could produce.
[–3]: For each color pair, you may pay that mana. Create X X/X green and blue Elemental creature tokens, where X is the number of times you do.

First mate—Each nonland card in your starting deck is an instant or has flash. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Flash
When Mable enters, you gain 2 life and draw a card.

Menace
Whenever Margarete or another creature you control dies, up to one target creature you control cackles. (Put a menace counter on it. If it already has menace, it deals 1 damage to each opponent instead.)
Once each turn, when Margarete or another creature you control with menace dies, you may torment each opponent. (They lose 3 life unless they discard a card or sacrifice a nonland permanent.)

Whenever an opponent activates an ability of a permanent, if it isn't a mana ability, you gain 1 life and create a Gold token. (It's an artifact with “Sacrifice this artifact: Add one mana of any color.”)

Protection from sorceries
Whenever Magdel, Caller of Souls attacks, create a 1/1 white Spirit creature token with flying that's tapped and attacking for each storied permanent you control. Exile the tokens at end of combat. (Enchantments and legendary permanents are storied.)

Transcend (Activate as a sorcery to gain the next type and a +1/+1 counter.)
When Mahara enters, if you cast them, destroy all other creatures.
{W}{B}: Angel — You gain 4 life and amass Soldiers 4. (Put four +1/+1 counters 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.)
{5}{W}{B}: Elder — Amass Soldiers 20.

Indestructible
Whenever this creature enters or transforms into Mahara, recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)
At the beginning of your end step, if you control four or more creatures, transform Mahara.

Armies you control attack each combat if able.
At the beginning of combat on your turn, recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)

Double strike, vigilance
Whenever Major Benjamin Stout enters, attacks, or dies, recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)

Haste
Sacrifice a creature or discard a card or reappropriate or pay 2 life: Makias, Marked Marauder gets +1/+0 until end of turn. (To reappropriate, exile exactly two cards from your hand and/or graveyard.)

[+1]: Scry 2. Whenever one or more creatures you control deal combat damage to a player this turn, draw a card.
[–2]: Create a token that's a copy of target creature you control, except the token is 4/4 and has vigilance.
[–7]: You get an emblem with “At the beginning of your draw step, draw two additional cards” and “Creatures you control get +1/+1 for each card you've drawn this turn.”

When Makshi, Patron of Blades enters, search your library for an Equipment card, reveal it, put it into your hand, then shuffle. Add {W}{U}{B}{R}{G}. Spend this mana only to cast Equipment spells and activate abilities of Equipment.

[+2]: Up to one target creature gains deathtouch until your next upkeep.
[–3]: Target player sacrifices a creature and discards a card.
[–8]: Exile all creature cards from all graveyards, then create an X/X black Horror creature token with indestructible, where X is the total power of creatures exiled this way.

Whenever a non-Serf creature you control enters, create a 0/1 black Serf creature token.
Sacrifice a Serf: Target creature you control gets +0/+1 until end of turn.

Double strike
Improve {1}{R/W} ({1}{R/W}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
At the beginning of combat on your turn, if you control three or more embattled creatures, you may search your library for an artifact, enchantment, or Angel card, reveal it, put it into your hand, then shuffle.

[+1]: Exile up to one target tapped creature.
[–2]: Create a 4/4 white Angel creature token with flying.
[–3]: Destroy all creatures. You gain 1 life for each creature destroyed this way.
[–7]: You get an emblem with “At the beginning of each end step, you gain life equal to twice the life you've lost this turn.”

[+1]: Discard a card. If you did, draw a card.
[–2]: Create a Bullet token. Until end of turn, if a Bullet you control would deal damage, it deals that much damage plus 1 instead. (It’s an artifact with “{T}, Sacrifice this artifact: It deals 1 damage to any target.”)

Deception {2}{U} ({2}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Marilye deals combat damage to a player, you may search your library for an artifact card with mana value less than or equal to that amount of damage, put it onto the battlefield, then shuffle.

Deception {2}{U}{U} ({2}{U}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
As long as it's your turn, Marilye is a 3/2 Elf Rogue creature with hexproof and indestructible.
[+1]: Tap target permanent. It doesn't untap during its controller's next untap step.
[–2]: Exile the top five cards of target opponent's library. You may cast any number of cards exiled this way with total mana value less than or equal to the amount of damage dealt to them this turn without paying their mana costs.

You may spend mana as if it was mana of any color to cast cards exiled with Marilye.
[+1]: Exile the top card of each opponent's library. Until end of turn, you may cast spells from among those exiled cards.
[–3]: Exile target creature. You may cast that card. If you don't, return it to its owner's hand.
[–7]: Gain control of up to five target nonland permanents.

Marin Polgek, Academy Heiress has hexproof as long as you control three or more enchantments.
{1}{W/U}{W/U}: Create a token that's a copy of target enchantment you control.

First mate—Each nonland card in your starting deck has “destroy,” “die,” “graveyard,” and/or “mill” in its printed rules text. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Deathtouch
When Marisa enters, if it was cast, you may put target permanent card from a graveyard onto the battlefield under your control.

Renown 1
When Marshal Jin Guiying becomes renowned, you may search your library for an artifact or enchantment card, reveal it, put it into your hand, then shuffle.