msem-instigator

{1}, Tap an untapped creature you control: Leaping Dancer gets +0/+1 and gains flying until end of turn. Then if you've activated this ability three or more times this turn, transform Leaping Dancer.

Reach
{1}: Untap Leapweb Lurker.

Whenever target creature deals combat damage to a player this turn, draw two cards.
Fuse (You may cast one or both halves of this card from your hand.)

Once each turn, when a player loses life, you may harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Each opponent loses 1 life and you gain that much life.

Counter target instant or sorcery spell you don't control unless its controller copies it twice. You gain control of those copies and may choose new targets for them.

As an additional cost to cast this spell, exile a card from your graveyard.
Counter target spell with mana value less than or equal to the exiled card's mana value.

Exile target creature or planeswalker. You gain 4 life.

Create three 2/1 red and white Fox creature tokens.

Exile all creatures, then for each creature exiled this way, you may return it to the battlefield under its owner's control. For each creature you didn't return to the battlefield this way, its owner may search their library for a basic land card and put it onto the battlefield tapped. Each player that does shuffles.

Destroy target creature or planeswalker. Create a 1/1 black Rat creature token with “This creature can't block.”

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.

As an additional cost to cast this spell, sacrifice a creature.
Target creature gains +4/+4 until end of turn.

Trample
When Leech-Encrusted Div enters, judge each creature you control. (Honor it by putting a +1/+1 counter on it or condemn it by sacrificing it to draw a card.)

When Leech-Ridden Corpse dies, each opponent loses 1 life and you gain 1 life.

Breach (Whenever this deals combat damage to a player, you may have it become an Aura Curse until your next turn. Attach it to that player.)
Once during each of your turns, you may cast a spell with mana value 3 or less that targets a cursed opponent or a permanent a cursed opponent controls by paying life equal to its mana value rather than its mana cost.

When Leery Sortie enters, create two 1/1 green Scout creature tokens.
{R}, Sacrifice Leery Sortie: Target creature can't block this turn.

Each player chooses a nonland permanent they control, then sacrifices the rest.

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.

When Left for Dead enters, create four 1/1 red Human Survivor creature tokens. Those tokens gain haste until end of turn.
At the beginning of your end step, sacrifice a Survivor. If you do, draw a card. Then if you control no Survivors, sacrifice Left for Dead.

Enchant creature
As Legacy of Dawn Hill enters, choose a creature type.
Enchanted creature gets +2/+0, has first strike, and is the chosen type in addition to its other types.

Enchant creature
As Legacy of Frondpond enters, choose a creature type.
Enchanted creature gets +2/+1, has deathtouch, and is the chosen type in addition to its other types.

Enchant creature
As Legacy of Highpoint enters, choose a creature type.
Enchanted creature gets +2/+2, has flying, and is the chosen type in addition to its other types.

Flash
Enchant creature
As Legacy of Northrime enters, choose a creature type.
Enchanted creature gets +1/+4 and is the chosen type in addition to its other types.

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.