msem-instigator

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
Target creature you control gets +1/+0 until end of turn if you're in a renaissance. Then that creature deals damage equal to its power to target creature you don't control.

When Fabled Chishou enters, create a token that's a copy of it, except it doesn't have this ability.
At the beginning of each end step, if Fabled Chishou isn't in a pack, sacrifice it. (Two or more creatures you control with equal power are in a pack.)

(Choose only one work as a sorcery to add its ability.)
When Fables of the Ill-Fated enters, destroy target nonland permanent.
{B}: The Witch's Temple
Whenever a nonland permanent you control dies, each opponent loses 1 life.
{3}{G}: Enter the Nest
{3}{G}, Sacrifice two lands: Create a 0/0 green Wurm creature token with “This creature gets +1/+1 for each permanent card in your graveyard.” Activate only as a sorcery.

When Fallen Dynasty Jailer enters, target opponent exiles a card from their hand. When Fallen Dynasty Jailer is no longer on the battlefield, the exiled card's owner puts it on the top or bottom of their library.

Flash
Flying
When Fang Luo enters, exile target spell or creature an opponent controls with mana value 4 or less, then its owner puts it onto the battlefield face down. (It's a 2/2 creature.)

Wu Xing (Add effects based on the number of colors of mana spent to cast this spell.)
1 | Mill five cards. An opponent separates the milled cards into two piles. Put one pile into your hand.
5 | You may cast a nonland card from the other pile without paying its mana cost.

[+1]: Until your next turn, whenever up to one target permanent deals damage to another permanent or player, it deals that much damage to itself.
[–X]: When you next cast a noncreature spell with mana value X or less this turn, copy it. You may choose new targets for the copy.
[–2]: Create an X/X blue Spirit creature token, where X is the number of colors of mana you've spent to cast spells this turn.

{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.

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.

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

Fiendish Yaoguai can't block.
Scavenge {5}{B} ({5}{B}, 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.)

Wu Xing (Add effects based on the number of colors of mana spent to cast this spell.)
1 | Fiery Portent deals 5 damage to target creature or planeswalker.
3 | Surveil 3.

Choose one —
• Return target permanent card from your graveyard to your hand.
• Destroy target artifact or enchantment.

Target creature gains double strike until end of turn.
Showcase {2}{R}{R} (Then if you cast this for its showcase cost, create a 1/1 red Bard creature token that can't block and exile this. Whenever it attacks, you may cast a free copy of this.)

Choose target creature you control, then choose two —
• Put a +1/+1 counter on it.
• Put a first strike counter on it.
• Put a trample counter on it.

When Flame Juggler dies, it deals 3 damage to each opponent.

Once each turn, when you cast an instant or sorcery spell, you may exile the top two cards of your library if you cast it for its showcase cost, otherwise, look at the top two cards of your library, then put one on the bottom of your library and exile the other. You may play cards exiled this way until you exile one or more other cards with For the Court of the Queen.

{T}: Add {B} or {R}. You lose 1 life unless you have less life than an opponent.

Return target instant or sorcery card from your graveyard to your hand. Forbidden Wisdom deals damage to up to one target creature or planeswalker equal to that card's mana value.
Exile Forbidden Wisdom.

When Forebear of Hibernation enters, each player may search their library for a creature card, reveal it, put it into their hand, then shuffle. Then you choose a nonland card name.
Spells with the chosen name cost {2} more to cast.

When Forerunner of the Briar enters, sacrifice two lands. When you do, choose one —
• Create a 3/3 green Beast creature token.
• Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

When Form of the Sunbird enters, it deals 4 damage to each creature. Your life total becomes 4.
If you would lose the game, instead transform Form of the Sunbird.

{T}: Add {B} or {G}. You lose 1 life unless you have less life than an opponent.