msem-instigator

Whenever Lakeside Trickster becomes tapped, up to one target creature phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

{T}: Add {U}. Spend this mana only to activate an ability or cast an instant or sorcery spell.

Other Actors you control get +1/+1.
Whenever a permanent you control transforms, Lantern Tender deals 2 damage to any target and you gain 2 life.

When Last-Thought Feeder dies, fateseal 2. (To fateseal 2, look at the top two cards of an opponent's library, then put any number of them on the bottom of that player's library and the rest on top in any order.)

First strike
{R}, Discard a land card: Put a +1/+1 counter on Lavamancer Adept. It gains menace until end of turn.

When Leader of Resistance enters, you may search your library for a Rebel creature card, reveal it, put it into your hand, then shuffle.
Other Rebel creatures you control get +1/+1.

Flash
When Leafdown Ambusher enters, create three colorless artifact tokens named Arrow. They have “{T}, Tap an untapped creature you control, Sacrifice this permanent: The tapped creature fights target creature you don't control. Activate only as a sorcery unless this permanent entered this turn.”

Lifelink
Menagerie — When Leafdown Glimmerfox enters, if there are five or more creature types among creatures you control, exile another target nonland permanent until its controller's next end step.

Trample
Leafdown Hunk enters with two +1/+1 counters on it if you control another creature with power 4 or greater.

When Leafdown Lookout enters, if you control another Scout, draw a card, then you may put a land card from your hand onto the battlefield tapped.

Whenever you cast an instant, sorcery, or Wizard spell, Leafdown Sizzlemage gets +1/+0 until end of turn.

Breach (Whenever this deals combat damage to a player, you may have it become an Aura Curse until your next turn. Attach it to that player.)
Once during each of your turns, you may cast a spell with mana value 3 or less that targets a cursed opponent or a permanent a cursed opponent controls by paying life equal to its mana value rather than its mana cost.

Vigilance
Creatures you control with a +1/+1 counter on them have mentor. (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Creatures you control with no +1/+1 counters on them have training. (Whenever this creature attacks with another creature with greater power, put a +1/+1 counter on this creature.)

Heroic — Whenever you cast a spell that targets Leina Tower Sentry, put a +1/+1 counter on Leina Tower Sentry and you gain 1 life.

Whenever you upgrade another creature you control, upgrade Lelin, the Wise. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Flying
• First strike
• Vigilance
• Lifelink
• Hexproof

Whenever you cast a spell during another player's turn, monstrosity 1. (If this creature isn't monstrous, put a +1/+1 counter on it and it becomes monstrous.)

Encourage ({T}: Another target creature you control gets +1/+1 until end of turn. Encourage only as a sorcery.)
Whenever Leotau Rider encourages a creature, that creature gains trample until end of turn.

Flying

{T}: Exile two target creature and/or land cards from a graveyard. Create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)
{B}{G}, Sacrifice two Vials: Sacrifice Leticia Petrine, then return her to the battlefield transformed under her owner's control.

Whenever Lha Maria blocks a creature, change Lha Maria's base power and toughness to that creature's power and toughness

{B}, Sacrifice a creature: Put a +1/+1 counter on Lightwrencher.

Flash
Whenever a creature you control deals combat damage to a player, create a Treasure token, then exile the top card of that player's library. You may play cards exiled this way for as long as they remain exiled.

Haste
Deploy 5 (As this enters, you may tap any number of other creatures you control with total power 5 or more.)
When Line Officer enters deployed, it deals 3 damage to each creature your opponents control.

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