msem-instigator

At the beginning of your end step, if you lost 2 or more life this turn, create a 1/1 black Bird creature token with flying. If you lost 4 or more life this turn, instead create a 3/3 black Cat creature token with deathtouch. If you lost 6 or more life this turn, instead create a 5/5 black Golem creature token with trample.

Creatures can't attack you or planeswalkers you control unless their controller pays {X} for each of those creatures, where X is the number of attacking creatures.

Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.
{2}{W}{B}: Ishim's Meddling becomes a 4/4 Angel creature with flying and vigilance until end of turn.

{2}{R}, Tap an untapped creature or Karina planeswalker you control: Copy target instant or sorcery spell, activated ability, or triggered ability. You may choose new targets for the copy. Activate this ability only once each turn.

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.

Whenever one or more creatures you control deal damage to a player, put a charge counter on Lake of Rage.
{T}: Add {C}.
{T}, Remove a charge counter from Lake of Rage: Add one mana of any color.

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.)

Lava Plume deals 3 damage to any target.
At the beginning of each end step, if you have 5 or less life, you may pay {R} and exile Lava Plume from your graveyard. If you do, it deals 3 damage to any target.

Lavatrailer enters tapped.
Whenever a creature attacks you, if Lavatrailer is tapped, Lavatrailer deals 1 damage to it.

Enchant player
At the beginning of enchanted player's upkeep, that player loses 1 life and you gain 1 life.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever Loyal Firestarter attacks, you may cast an instant or sorcery spell from your hand with mana value less than or equal to Loyal Firestarter's power without paying its mana cost.

When Lucien's Trail enters, exile target creature or enchantment an opponent controls.
Sacrifice another permanent: Lucien's Trail becomes a copy of the exiled card until end of turn.

[+1]: Until your next turn, up to one target creature gets -2/-1 and gains “When this creature dies, merge it under Lucien, the Ravenous. He has its abilities.”
[–2]: Merge target creature under Lucien, the Ravenous. He has that creature's abilities.
[–6]: For each card merged with Lucien, create a token that's a copy of that card, except it has haste.

If a triggered ability of equipped creature would trigger, it triggers an additional time.
Equip {2}

Whenever Luna enters or phases in, each player loses 1 life.
Whenever a player casts a spell or a creature attacks, Luna phases out.

When Lunar Vigil enters, draw a card, then scry 2.
If you would draw one or more cards, you may instead put a night counter on Lunar Vigil and draw that many cards minus one.
Sacrifice Lunar Vigil: Target player draws a card and adds {R} for each night counter on it.

Haste
When Magma Crawler enters, creatures you control with flash or haste get +1/+1 until end of turn.

Harness (You may tap a creature you control as you cast this spell. If you do, reduce this spell's mana cost by that creature's power.)
Magnitude deals X damage to each player and each creature without flying that didn't harness it.

This spell costs {1} less to cast for each differently named creature you control.
Whenever a creature you control enters, if it has a different name than each other creature you control and card in your graveyard, draw a card.

{X}{U}{U}: Marine Monster can't be blocked by creatures with mana value X or less this turn.

Whenever another creature you control dies, put a +1/+1 counter on Marshy Marauder.
When Marshy Marauder dies, create a 1/1 green Insect creature token for each counter on it.

Lifelink
If you would gain life, you may put that many +1/+1 counters on another creature you control instead.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever an experience ability puts a +1/+1 counter on a creature you control, put a +1/+1 counter on that creature.

First strike
Mauling Mother gets +1/+1 for each other creature you control.

When Maven of Fear enters, mill two cards.
Maven of Fear gets +2/+1 and has menace as long as six or more cards are in your graveyard.