msem-instigator

{2}{R}{R}, Exile an instant or sorcery card from your graveyard: Fervid Dragonheart gets +1/+2, gains flying, and becomes a Dragon until end of turn.

Whenever a creature you control dies, put a rot counter on Fester Swarm and you gain 1 life.
{B}{G}, Remove two or more rot counters from Fester Swarm: Create a 1/1 green Insect creature token, then put a +1/+1 counter on it for each rot counter removed this way.

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

When Festering Shipwreck enters, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)
At the beginning of each player's upkeep, that player sacrifices a nonland permanent.

At the beginning of your upkeep, mill a card.
{1}, Exile three cards from your graveyard: Put a -1/-1 counter on target creature.

When Festering Waif enters, each opponent mills two cards.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

When Festival Celebrants enters, put a +1/+1 counter on each creature you control.

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
{T}: Add {C}. If you're in a renaissance, add one mana of any color instead.
{3}, {T}: Scry 1.

Inspired — Whenever Festival Decorator becomes untapped, draw a card.

When Festival Rioters enters, create a colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.”
{1}{R}: Festival Rioters gets +2/+0 until end of turn.

Choose one —
• Festival Sabotage deals 2 damage to any target.
• Audition for red. (Create a 1/1 Construct Actor creature token, a Warrior Role giving 3/2 and trample, or a Wizard Role giving 2/2 and prowess. Roles replace older ones.)

Harmony — Create a 1/1 white Bird creature token with flying.
{4}: Harmonize. (Trigger up to one harmony of one permanent you control.)

Destroy target enchantment and all other enchantments with the same name as that enchantment.
Draw a card.

Destroy target artifact and all other artifacts with the same name as that artifact.
Draw a card.

Target creature and all other creatures with the same name as that creature get +2/+2 until end of turn.
Draw a card.

Return target nonland permanent and all other permanents with the same name as that permanent to their owners' hands.
Draw a card.

Enchant creature you control
When Festive Euphoria enters, you gain life and draw cards equal to enchanted creature's power.
Enchanted creature can't be blocked by creatures with power 2 or less.

Choose one —
• Target attacking creature gets +2/+2 until end of turn.
• Destroy target artifact.

Festive Servitor gets +1/+1 for each color among spells you've cast this turn.
{2}: Add one mana of any color.

When Fetching Gancanagh dies, draw a card. At the beginning of the next end step, up to one target creature you control becomes a copy of Fetching Gancanagh.

{B}: Fetid Nibbler gains deathtouch until end of turn.

When Feverish Noble dies, you draw two cards and you lose 2 life.

{T}: Add {C}.
{T}, Pay 1 life: Add {G} or {U}.

Whenever another nontoken creature you control dies, create a 1/1 black Rat creature token with “This creature can't block” if this is the first time this ability has resolved this turn. Otherwise, Ffion, Famine Warcaller deals 1 damage to each player.

Whenever a creature card is put into your graveyard from anywhere, it gains revive until the beginning of your next end step. The revive cost is equal to its mana cost increased by {1}. (Pay that card's mana cost increased by {1}, Exile that card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)