msem-instigator

{T}, Pay 1 life: Add {W} or {B}.
{1}, {T}, Sacrifice Legitimate Establishment: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Ward—{2} or 2 life. (Whenever this becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2} or 2 life.)
Whenever another permanent becomes the target of a spell you control, create a token that's a copy of it. Sacrifice that token at the beginning of your next turn's end step.

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.)

When Leija's Greenblade enters, you may pay {G}. If you do, destroy target artifact or enchantment.

Whenever Leija, the Bloodied Queen attacks, you may pay {R}{R}{R}{R}. If you do, it deals 4 damage to each other creature, each player, and each planeswalker.

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

You may look at the top card of your library any time.
Once each turn, you may cast a spell from the top of your library.
Whenever you cast a spell from a library, create a 1/1 blue Elemental creature token with vigilance.

Flying
At the beginning of your end step, put a +1/+1 counter on Lepidopteradator if you're horrific. Otherwise, sacrifice it. (You're horrific as long as you've sacrificed a permanent or discarded a card this turn.)

Converge — Let It Burn enters with a charge counter on it for each color of mana spent to cast it.
{1}{R}, Remove a charge counter from Let It Burn: It deals 3 damage to any target.
When there are no charge counters on Let It Burn, return it to its owner's hand.

When Lethal Storyboarding enters, create two 1/1 colorless Construct Actor creature tokens.
Whenever a creature you control deals combat damage to a player or planeswalker, sacrifice it. When you do, choose one —
• Return a creature card with mana value 3 or less from your graveyard to the battlefield tapped.
• Draw a card.

{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.

{T}: Add {C}.
{2}, {T}: For each color among cards in your graveyard, add one mana of that color.

When Leyline Invoker enters and at the beginning of your upkeep, you may mill two cards.
{5}{B}, {T}, Sacrifice Leyline Invoker: Return target creature card from your graveyard to the battlefield. This ability costs {1} less to activate for each creature card in your graveyard.

Trample
When Leyran Alpha enters, create two 2/2 green Wolf creature tokens with haste.
Whenever a creature you control deals damage to an opponent, put a +1/+1 counter on that creature.

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.

Shimmer (Whenever this creature attacks, create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the end step.)
Lha Elite's power is equal to the number of tokens you control.

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

[+2]: Create two 0/0 colorless Reflection creature tokens.
[–2]: Distribute four +1/+1 counters among any number of target creatures you control. You may tap or untap each of those creatures.
[–7]: You get an emblem with “Creature tokens you control can't leave the battlefield.”

[+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.”

Equipped creature has double strike.
Whenever equipped creature attacks, 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.”)
Abilities of Idols you control that target equipped creature cost {1} less to activate.
Equip {2}{W}

[+2]: Scry 2, then you may draw a card. If you don't, Liactru Stormheart deals 2 damage to any target.
[–4]: Create a 4/4 blue and red Elemental creature token. It gains flying, vigilance, and haste until end of turn.
[–10]: For each player, create a token that's a copy of target permanent that player controls. You get an emblem with “Permanents you control have hexproof.”

Trample
Lian Taizi gets +1/+1 for each card in your hand.
When Lian Taizi enters, return any number of target cards with different mana values from your graveyard to your hand.

{X}{W}{W}: Prevent the next X damage that would be dealt to target creature you control this turn. Whenever damage is prevented this way, you gain that much life.

Wu Xing (Add effects based on the number of colors of mana spent to cast this spell.)
1 | Discard up to two cards, then draw that many cards plus one.
3 | For each color of mana spent to cast this spell, add one mana of that color.

Lifelink
If a creature or planeswalker would die, instead exile it and put a +1/+1 counter on Librarian of Whispers.