msem-instigator

When Lurking Angler enters, if seven or more cards are in your graveyard, draw a card. Otherwise, mill two cards.

Put a +1/+1 counter on target creature. It can't be blocked this turn.(Cast a copy of this spell once while this creature is on the battlefield.)

Menagerie — When Lurking Feralynx enters, if there are five or more creature types among creatures you control, you may search your library for a card named Lurking Feralynx, reveal it, put it into your hand, then shuffle.

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.)
Hexproof

Concord — Lurking Lahasia has first strike and lifelink as long as there are four or more card types among permanents you control.

Destroy target creature that was dealt damage this turn, then create a 3/2 black Mutant Horror creature token.

Target creature gets +3/+3 and gains haste until end of turn.

At the beginning of your end step, any number of target players mill three cards.
{5}{U/B}, {T}: You may cast target instant or sorcery card from an opponent's graveyard without paying its mana cost. Activate only as a sorcery.

Enchant land
Enchanted land has “{T}: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.”

When Lust for Life enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Augmented — Whenever a creature you control enters, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, you may sacrifice Lust for Life. If you do, create a token that's a copy of that creature.

Enchant creature
Enchanted creature has distorted. (It can be blocked by tapped creatures but not untapped creatures.)
{1}{B}: Enchanted creature can't block this turn.

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)
{1}{U}, Discard Lusterwing Owl: Return target enchantment to its owner's hand.

When Lustrebloom Diviner enters, create a Treasure token.
At the beginning of each end step, if you spent three or more colors of mana to cast spells this turn, you gain 3 life. If you spent {W}{U}{B}{R}{G}, draw a card.

Flying
When Lustrous Devout enters, choose one —
• Put a +1/+1 counter on Lustrous Devout.
• Create a colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.”

Flying
Prismatic — Whenever you cast a multicolored spell, scry 1.

Whenever Lute Tickler attacks, you may goad target creature defending player controls. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

When Lysander Jal enters, create a token that's a copy of another target noncreature permanent you control.
Whenever you cast a spell from your graveyard, return target permanent card from your graveyard to your hand.

Flying
Whenever another creature you control enters, you may search your library for an instant or sorcery card with the same mana value as that creature, reveal it, put it into your hand, then shuffle.

Attacking Pirates and Rogues you control get +1/+0.
{2}{U}: Tap target creature an opponent controls.

When Lysene enters, you may search your library for a card with foretell, reveal it, put it into your hand, then shuffle. The next card you foretell this turn costs {0} to foretell.
Whenever you foretell a card or cast a foretold spell, Pirates and Rogues you control get +1/+0 until end of turn. Up to one target Pirate or Rogue you control can't be blocked this turn.

Flying, haste
Whenever Ma'Long deals combat damage to a player, draw a card, then add that much mana in any combination of {U} and/or {R}. Until end of turn, you don't lose this mana as steps and phases end.
Instant and sorcery cards in your hand have showcase. The showcase cost is equal to the card's mana cost plus {2}. (If you cast it for its showcase cost, create a 1/1 red Bard creature token that can't block and exile that card. Whenever the Bard attacks, you may cast a free copy of the exiled card.)

Create a tapped Treasure token.
Memento {2}{B}{B} (You may cast this from your graveyard for {2}{B}{B}. If you do, put it onto the battlefield transformed after it resolves. Exile it if it would leave the battlefield or not resolve.)

When Maaru, Tomb Guardian enters, create three Treasure tokens.
Each Treasure you control is an artifact creature with power and toughness each equal to the number of Treasures you control.

[+1]: Create a tapped colorless land token named Far-Off Lands with “{T}: Add one mana of any color.”
[–1]: Choose a color. Untap all lands you control that could produce that color.
[–6]: Draw a card for each differently named land you control.

Whenever you cast a spell, if it doesn't share a name with a permanent or a card in a graveyard, draw a card.