msem-instigator

Lost Explorer has first strike as long as it's attacking.
{1}{B}, Exile Lost Explorer from your graveyard: Crystallize. (Put a +1/+1 counter on a creature you control or create a Treasure.)

When Lost Kitten leaves the battlefield, create a 1/1 white Peasant creature token.

Enchant opponent
When Lost Knowledge enters, enchanted player reveals their hand.
{1}, Sacrifice Lost Knowledge: Scry 2, then draw a card.

Choose two —
• You gain 3 life.
• Lost Memories deals 3 damage to any target.
• Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Counter target spell, activated ability, or triggered ability. Its controller chooses draw step, main phase, or combat phase. That player skips each instance of the chosen step or phase during their next turn. (Mana abilities can't be targeted.)

Glitch {2} (Remove one [restriction] for each time you pay the glitch cost.)
Put target creature [spell] on top of its owner's library.

Flying
Heretic (Whenever you cast a spell that doesn't share a color with this creature, it gets +1/+1 until end of turn.)

Lost Station enters tapped.
{T}: Add {U}.
{U}{U}: Until end of turn, Lost Station becomes a 2/2 Horror creature with “This creature can't be blocked.” Activate only if you're horrific.

Counter target spell. If a noncreature spell is countered this way, conjure a card named Fatigue and put it on top of your library. (It's a colorless sorcery that costs {2} with “Draw a card.”)

Target player discards two cards.

Exile target nonland permanent.

Put target nonland permanent on top of its owner's library.
Create a colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.”

Target creature gets +2/+2 until end of turn. Untap it.

Look at the top three cards of your library. Put one of them into your hand. Put Lost in Deep Storage and the rest on the bottom of your library in any order.

Enchant creature
Enchanted creature can't attack or block, and its activated abilities can't be activated.
Mirage {W/U} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Exile target permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Creatures can't attack you or planeswalkers you control unless their controller pays 2 life for each of those creatures.

This spell costs {1} less to cast if you've cast another spell this turn.
Destroy target creature.

Play with the top card of your library revealed.
You may play the top card of your library.
At the beginning of your end step, create an X/X green and blue Plant Elemental creature token with reach, where X is the top card of your library's mana value.

Put target artifact or enchantment with mana value less than or equal to the number of basic lands you control on the bottom of its owner's library.

Enchant creature
When Lost to the Elements enters, if enchanted creature isn't in a pack, tap it. (Two or more creatures with the same controller and equal power are in a pack.)
Enchanted creature doesn't untap during its controller's untap step.

Lifelink
{B}, Sacrifice Lostrite Evoker: Add {B}{B}{B}.

First strike, haste
Whenever Lothaire attacks, create a 0/0 colorless Reflection creature token that's tapped and attacking. Creatures you control get +1/+1 until end of turn.
{2}{R}{W}: Put a +1/+1 counter on each creature you control.

Whenever Lotus Acolyte attacks, it gets +1/+0 and gains lifelink until end of turn.

{T}: Add {C}.
{2}, {T}, Sacrifice Lotus Barrens: Destroy target nonbasic land an opponent controls. You and that land's controller each create a colorless land token named Lotus Spring with “{T}: Add one mana of any color.”