msem-instigator

Creatures you control get +X/+0 and gain first strike until end of turn.

You may cast this spell without paying its mana cost if it targets a creature with power 5 or greater and you control a Swamp and a Mountain.
Last Stop deals 11 damage to target creature. That creature loses indestructible until end of turn.

Flash
Flying
When Laughing Bird enters, you may return a creature you control to its owner's hand.

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.

Vanishing 1 (This creature enters with a time counter on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Whenever a creature you control deals combat damage to a player, put a time counter on Lavacore Elemental.

Whenever a player looks at one or more cards in your library or searches your library, Lavamind Elemental deals 2 damage to that player. (This includes you.)
At the beginning of your end step, look at the bottom card of your library. You may put it on top of your library.

Counter target spell unless its controller pays {4}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Exile up to one target permanent you control. Return it to the battlefield under its owner's control at the beginning of the next end step.
Recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)

Return any number of lands you control to their owner's hands. For each land returned this way, search your library for a land card, reveal it, then put it into your hand. Then shuffle.

Whenever a creature you control dies, you may pay {G}. If you do, draw a card.

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Whenever a Role becomes attached to Lead Athlete or you cast a spell that targets it, put a +1/+1 counter on Lead Athlete.

Attacking creatures get +2/+0 until end of turn. If you control a legendary creature, those creatures also gain first strike until end of turn.

Whenever Leading Clergy attacks, you may pay {W}. If you do, audition for white. (Create a 1/1 Construct Actor creature token, a Scout Role giving 2/3 and vigilance, or a Cleric Role giving 2/2 and lifelink. Roles replace older ones.)

When Leads Don't Die enters, mill four cards and you gain 4 life.
At the beginning of your upkeep, you may exile X cards from your graveyard and sacrifice Leads Don't Die. When you do, return target creature card with mana value X or less from your graveyard to the battlefield.

When Leafguard Larva enters or a creature you control scavenges it, return target card from your graveyard to your hand.
Scavenge {3}{G} ({3}{G}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

When Leafmantle Dryad enters, if you control a legendary creature, you may search your library for a basic land card and put it onto the battlefield tapped, then shuffle.

Reach
{1}: Untap Leapweb Lurker.

All creatures have haste and attack each combat if able.
{1}{R}: Led by Fury deals 1 damage to target attacking creature.

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

Bleed {B/R} (You may cast this spell for its bleed cost if an opponent has lost life this turn.)
Left for Carrion deals 4 damage to target creature.

Enchant creature
As Legacy of Siltbottom enters, choose a creature type.
Enchanted creature gets +3/+3 and is the chosen type in addition to its other types.

At the beginning of your end step, draw a card, then discard a card.
Whenever you cast a spell with mana value 5 or greater, if it's an instant or has flash, you may counter target spell.

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.)

At the beginning of your upkeep, invigorate 1. (Choose a creature with the least power among creatures you control and put a +1/+1 counter on it.)

Put target creature on the bottom of its owner's library.
Each player conjures a card named Fatigue and puts it on top of their library. (It's a colorless sorcery that costs {2} with “Draw a card.”)