Cards in graveyards can't leave the graveyard.
Cycling {2}

As an additional cost to cast this spell, sacrifice a creature.
Fall Upon Your Blade deals damage equal to the sacrificed creature's power to any target.
Cycling {2}

Enchant creature you control
When Fall from Nyx enters, destroy target artifact or land.
Enchanted creature gets +2/+0.

Fatal Flourish deals 4 damage to target creature. If excess damage is dealt this way, put that many +1/+1 counters on a creature you control.
Cycling {2}

Trample
Forestcycling {2}

When this land enters, sacrifice it. If you do, search your library for a basic Swamp or Mountain card, put it onto the battlefield tapped, then shuffle.
{2}{B}{B}{R}{R}, Discard this card: Create a 4/4 red Error creature token with menace.

Enchant creature
Enchanted creature gets +1/+1 and has vigilance and trample.

Fabric — When this creature enters, add X mana in any combination of colors, where X is the number of enchantments you control.
{1}{R}, Discard a card: Draw a card.

Field Laboratory enters tapped.
{T}: Add {G} or {U}.
{1}, Discard Field Laboratory: Scry 2.

Trample
Whenever you gain control of a permanent you don't own or a permanent you don't own enters under your control, it and Field Opportunist each get +2/+0 and gain haste until end of turn.

Enchant land
Enchanted land has “{T}: Add one mana of any color.”

Choose one or both —
• Target Kraken, Leviathan, Octopus, or Serpent creature you control gets +2/+1 until end of turn.
• Target creature you control fights target creature you don't control.

Before equipped creature would assign, deal, or be dealt damage, sacrifice Figy Berry. If you do, equipped creature gets +2/+2 until end of turn.
Equip {1}
{7}, Sacrifice Figy Berry: Destroy target nonland permanent.

Firebolt deals 2 damage to any target.
Flashback {4}{R}

Draw a card. If you control no creatures, create a 1/1 colorless Cyborg artifact creature token.

When Flags on High enters, create two 1/1 colorless Soldier creature tokens.
{1}{R}, Sacrifice Flags on High: Target creature you control gets +1/+0 and gains haste until end of turn. Activate only as a sorcery.

Flame Whip deals 4 damage to target creature or planeswalker.

Reach
{3}{R/G}: Flametip Goliath gets +2/+0, gains trample, and becomes a Giant in addition to its other types until end of turn.

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.

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.

Enchant creature you control
Enchanted creature gets +1/+1.
When this Aura enters, enchanted creature fights up to one target creature.

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.

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