msem-instigator

Whenever Knight of the Verdigris deals combat damage to a player, you may sacrifice it. If you do, search your library for a green legendary creature card, reveal it, put it into your hand, then shuffle.

Prowess
Whenever Knight-Academic attacks, scry 1.

{T}: Add {G} or one mana of any color among cards in your graveyard.

When Kofe-District Scholar enters, draw a card. If Kofe-District Scholar's paranoia cost was paid, draw two cards instead.
Paranoia {1}{U}{U} (You may cast this spell for its paranoia cost when a permanent you control leaves the battlefield.)

At the beginning of your end step, if an opponent lost life this turn, Kogane the Crimson Consort deals 2 damage to each opponent and you gain 2 life.

Kicker {X} (You may pay an additional {X} as you cast this spell.)
When Korrinary Warcaller enters, if it was kicked, search your library for a Rebel permanent card with mana value X or less, put it onto the battlefield, then shuffle.

Other creatures you control get +1/+1.
When Kotis, Promised General dies, you may return it to its owner's hand.

Whenever you cast a creature spell, 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.”)
Whenever you sacrifice an Idol, draw a card.

{3}{B}{B}: Return target Zombie creature card from your graveyard to the battlefield.
Whenever another creature you control enters from a graveyard or you revive a creature token, that creature gets +2/+0 and gains haste and menace until end of turn.

Art of war — At the beginning of your end step, if Kurayami Butcher dealt damage to an opponent, you may destroy target creature that was dealt damage this turn.

Whenever another nontoken creature you control dies, you may exile it. If you do, create a 2/2 colorless Spirit creature token.

Art of war — At the beginning of your end step, if Kuryu Swordsman dealt damage to an opponent this turn, you may have Kuryu Swordsman fight target creature you don't control. (Each deals damage equal to its power to the other.)

Flying

Whenever Lackeybot deals damage to a player, choose an artifact card with mana value X or less at random, where X is the amount of damage dealt. You may create a token that's a copy of that card.

Trample
{2/G}{2/G}, {T}: Put two +1/+1 counters on Laden Bruiser.

Deathtouch
The first instant or sorcery spell with mana value 3 or less you cast each turn has siphon. (Each -1/-1 counter you put on your creatures up to their remaining toughness while casting this pays for {1}.)

Menace
Whenever a nontoken creature you don't control dies, create a token that's a copy of that creature except it's a colorless Spirit. Exile it at the beginning of your next end step.

{T}: Target land you control becomes the basic land type of your choice until end of turn.
At the beginning of each end step, if you spent three or more colors of mana to cast spells this turn, surveil 1.

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.”