As long as its not your turn, spells you cast cost {1} less to cast.

Haste
Whenever a player casts a spell, if no mana from a basic source was spent to cast it, Flaw in the System deals 2 damage to that player.

Whenever a creature dealt damage by Fleshbearer this turn dies, integrate that creature.
Fleshbearer gets +2/+0 and has menace as long as a creature card is integrated onto it.

Vigilance
{T}: Surveil 1.
Surface {3}{U}

Approval — When Flock Favorites enters, exile the top X cards of your library, where X is the number of colors among permanents you control. Until the end of your next turn, you may play those cards.

Whenever Floe Master enters or another creature you control surfaces, tap up to one target creature and put a stun counter on it.
Surface {5}{U}{U}

Flash
At the beginning of your end step, if you control three or more untapped lands, put a +1/+1 counter on Flow Grandmaster.

Flash
Flying
{VP}{VP}{VP}: Draw a card.

Flying
Whenever you amp it up, draw a card, then discard a card.

This spell costs {1} less to cast if it targets a spell you control and costs {1} less to cast if it targets a spell with mana value 3 or less.
Copy target spell. You may choose new targets for the copy.

Flying
{T}: Add {C}.
Spellcharge 4

Flying
Amity — Whenever you attack with Fluttering Firefly and exactly one other creature, target creature you control gets +2/+0 until end of turn.

Deathtouch
{1}{W}, {T}: Create a Berry token.
{2}{B}, Sacrifice a Berry: Put a +1/+1 counter on Foraging Grub.

Return target creature to its owner's hand. If you've cast another instant or sorcery spell this turn, draw a card.

Equipped creature gets +2/+2 and can't be blocked by more than one creature.
Equip {4}

Enchant permanent
Enchanted permanent can't attack, block, or wander.

When Forgemaster Dreadnought enters, create three Treasure tokens.
Spellcharge 9

Choose target card in a graveyard other than a basic land. Search its owner's graveyard, hand, and library for any number of cards with the same name as that card and exile them. If their library is searched this way, they shuffle it. You gain 1 life for each card exiled this way. That player draws a card for each card exiled from their hand this way.
Flashback {3}{B}

At the beginning of your end step, if a creature died this turn, exile the top card of your library. Until the end of your next turn, you may play that card.

Fortress Arena enters tapped.
{T}: Add {R} or {W}.
{2}{R}{W}, {T}, Sacrifice Fortress Arena: Draw a card.

{T}: Add {C}. You may sacrifice Fortune Bearer. If you don't, you can't spend this mana to cast a spell from your hand.
Surface {5}{U}{U}. Fortune Bearer surfaces transformed.

Flying
If a source would deal 2 or more damage to Fragile Soul, prevent that damage.

Create a tapped Leyshard token.

Whenever you amp it up, Fraying Gearhead gets +1/+0 and gains first strike until end of turn.