msem-instigator

Flash
When Keeper of Codices enters, you may exile target artifact or enchantment you control. If you do, return that card to the battlefield under its owner's control at the beginning of the next end step.

As an additional cost to cast this spell, return any number of creatures you control to their owner's hands. This spell costs {2} less to cast for each creature returned in this way.
Trample, ward {3}
Keepers of the Rundfora's power and toughness are each equal to twice the number of cards in your hand.

This spell costs {1} less to cast for each permanent you control that's an artifact and/or a token.
When Kellythross's Collector enters, you may return another target nonland permanent to its owner's hand.

This spell costs {1} less to cast for each embattled creature you control. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)
Haste
Whenever Knights of the Burning Pyre attacks, it deals X damage to each opponent, where X is the number of embattled creatures you control.

Paranoia {2}{U} (You may cast this spell for its paranoia cost when a permanent you control leaves the battlefield.)
Put target artifact or creature on top of its owner's library.

Flying
Whenever an opponent discards a card, you may exile it. If you do, create a 1/1 black Bird creature token with flying and “This creature can't block.”
{B}, Sacrifice three Birds: You may cast a card exiled with Krahen, Dusk's Call without paying its mana cost.

When Lammasu Roost enters, create a 2/2 blue Lammasu creature token with flying.
{3}{U}: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

{T}: Add {G}.

Destroy target creature or planeswalker. Create a 1/1 black Rat creature token with “This creature can't block.”

As Legacy Foundations enters, you may reveal a Plains or Swamp card from your hand. If you don't, Legacy Foundations enters tapped.
{T}: Add {W} or {B}.

When Legacy Warmask enters, return target creature card with mana value 2 or less from your graveyard to the battlefield, then attach Legacy Warmask to that creature.
Equipped creature gets +1/+1.
Equip {1}

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.)
Lifelink
When Leyran-Pack Outcast attacks, if it's alpha, each player sacrifices a creature.

[+1]: Until your next turn, another target non-Aura permanent becomes a land with “{T}: Add one mana of any color” and loses all other card types and abilities.
[–2]: Create a 1/1 blue Spirit creature token with flying. Draw a card.
[–7]: You get an emblem with “At the beginning of your end step, create a 6/6 green and blue Spirit Warrior creature token with trample named Echo of Lhosei.”

When Lie in Ambush enters, create a tapped 3/3 green Beast creature token.
When Lie in Ambush leaves the battlefield, you may have target creature you control fight target creature you don't control. (Each deals damage equal to its power to the other.)

Destroy target creature. Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Lijing has indestructible as long as you control two or more other Foxes.
At the beginning of your upkeep, invigorate 1 another Fox. (Choose another Fox with the least power among other Foxes you control and put a +1/+1 counter on it.)
Once each turn, when another Fox you control enters, you may pay {1}. If you do, draw a card.

First mate — Each nonland card in your starting deck has “+1/+1 counter” or “harmonize” 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.)
Once each turn, if one or more +1/+1 counters would be put on a permanent you control, you may put twice that many of those counters on it instead.
Once each turn, if you would trigger a harmony ability of a permanent you control, you may have that ability trigger twice instead.

When Limbhacker Blade enters, each opponent discards a card.
Equipped creature gets +2/+0.
Equip {2}

Aura and Equipment spells you cast cost {1} less to cast.

Trample, haste
Whenever Lisseria, General of Kanaa attacks, you may exchange its power with the power of target creature defending player controls until end of turn.

Ward—Pay 3 life.
Whenever you cast an instant or sorcery spell, recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)

Livia's name is Senaturian Legion in addition to its other names as long as it's on the battlefield.
At the beginning of your upkeep, conjure a card named Senaturian Legion into your hand, then discard a card. (It's a 1/1 Human Soldier for {W}{W} that gets +1/+1 for each other creature on the battlefield named Senaturian Legion.)
Other Soldiers you control have haste.

Trample
Whenever Living Archipelago enters or attacks, up to two target lands you control voyage. (If they aren't being targeted by another spell or ability, they phase out.)
Whenever a land you control phases in, you may create a tapped token that's a copy of that land.

Flash
When Lizaveth's Surveyor enters, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
Lizaveth's Surveyor's power is equal to the number of artifacts you control.

When Lock Away enters, exile target nonland permanent an opponent controls until Lock Away leaves the battlefield.