msem-instigator

{T}: Add {C}.
{T}, Sacrifice Fluctuating Locale: Rediscover a land card. (Look at the top card of your library. You may reveal it and put it into your hand if it's a land card. Otherwise, put it back or into your graveyard.)

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

Forbidding Isle enters tapped unless you control a Swamp.
{T}: Add {U} or {R}.

As Foreboding Ruins enters, you may reveal a Swamp or Mountain card from your hand. If you don't, Foreboding Ruins enters tapped.
{T}: Add {B} or {R}.

Forgotten Attic enters tapped.
When Forgotten Attic enters, look at the top card of your library. You may put it into your graveyard.
{T}: Add {U} or {B}.

Forgotten Cryovault enters tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

{T}: Add {C}.
{T}: Add {C}{C}. Spend this mana only to cast spells from your graveyard.

{T}: Add {C}.
{1}, {T}, Sacrifice a creature: Create a 1/1 colorless Spirit creature token.

({T}: Add {B}.)
Forgotten Pit enters tapped.
Deathtouch
{2}{B}{B}: Forgotten Pit becomes a creature in addition to its other types until end of turn.

{T}, Pay 1 life: Add {R} or {G}.
{1}, {T}, Sacrifice Forgotten Shrine: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

({T}: Add {R} or {W}.)
Whenever Forgotten Steppe becomes tapped, you lose 1 life unless you control two or more basic lands.

{T}: Add {C}. Exile a card from your graveyard.
{3}: Until end of turn, Forgotten Temple becomes an X/X creature, where X is the number of cards exiled by it. It's still a land.
As long as a creature card with flying is exiled by Forgotten Temple, it has flying. The same is true for first strike, double strike, deathtouch, experience, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

Forlorn Path enters tapped unless you control one or fewer other lands.
{T}: Add {B} or {G}.
Cycling {2} ({2}, Discard this card: Draw a card.)

({T}: Add {U} or {B}.)
As Forlorn Ruin enters, you may pay {1}. If you don't, Forlorn Ruin enters tapped.

{T}: Add {C}.
{T}, Reappropriate: Add {W} or {B}. (Exile exactly two cards from your hand and/or graveyard.)

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

As Fortified Village enters, you may reveal a Forest or Plains card from your hand. If you don't, Fortified Village enters tapped.
{T}: Add {G} or {W}.

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

{T}: Add {C}.
{T}, Pay 1 life: Add one mana of any color. Activate only during an opponent's turn.

Frigid Highlands enters tapped unless you control an Island.
{T}: Add {R} or {G}.

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

Frondpond Grotto enters tapped unless you played it from exile.
{T}: Add {U} or {B}.

Frontier Base enters tapped unless you have 15 or less life.
{T}: Add {G} or {U}.

({T}: Add {U} or {R}.)
Frostfire Geysers enters tapped unless you control a basic Island or a basic Mountain.