msem-instigator

Exile the top two cards of your library. You may play one of them until the end of your next turn.
Motley — If there are five or more names among nonland permanents you control, you may play both of them until the end of your next turn instead.

Breach (Whenever this deals combat damage to a player, you may have it become an Aura Curse until your next turn. Attach it to that player.)
Once each turn, when a Curse you control becomes attached to an opponent, you may sacrifice it. If you do, reveal cards from the top of your library until you reveal a Curse card. Put that card onto the battlefield attached to that player, and the rest on the bottom of your library in a random order.

Menace
Whenever an opponent activates an ability that isn't a mana ability, Flensing Tormentor deals 1 damage to that player.

Put a +1/+1 counter on target creature. That creature gains first strike until end of turn.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
You don't lose unspent red mana as steps and phases end.
I, II — Add {R}{R}.
III — Create a 3/3 red Phoenix creature token with flying, haste, and “{R}: This creature gets +1/+0 until end of turn.”

Flooding Magma deals 2 damage to each creature except for equipped creatures you control.

Flourishing Mountain enters tapped.
As Flourishing Mountain enters, choose a basic land type.
Flourishing Mountain is the chosen type in addition to its other types.

Exile the top five cards of your library. You may play Dragon cards exiled this way as long as they remain exiled. You may play other cards exiled this way until the end of your next turn.

This spell has flash as long as you control a creature with flash or haste.
Discard up to two cards, then draw that many cards plus one.

When Fodder Goblins enters, create a 1/1 red Goblin creature token.

Until the end of your next turn, you may play a red card you own from outside the game. Add {R}{R}.

Any number of target creatures you control each fight target creature with power 3 or greater. (All fight damage happens simultaneously.)

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.

Target creature gets +2/+1 until end of turn. (Then exile this card. You may cast the creature later from exile.)

Whenever a player casts a spell, put a doom counter on Foreboding Presence.
At the beginning of each player's end step, if no spells were cast this turn, sacrifice Foreboding Presence. It deals damage equal to the number of doom counters on it to that player.

Forest Fire deals 4 damage to target creature or planeswalker. (Then exile this card. You may cast the creature later from exile.)

Heroic — Whenever you cast a spell that targets Forge Adept, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)
{6}{R}: Create a 3/3 colorless Golem enchantment artifact creature token. If mana from an artifact was spent to activate this ability, that token gains haste.

Choose one —
• Forge Trick deals 3 damage to target creature.
• Target creature gets +3/+0 until end of turn.

Attacking creatures you control have “{R}: This creature gets +1/+0 until end of turn.”
Armed — Whenever Forgeborn Barbarian attacks, add {R} for each equipped creature you control.

Choose one —
• Forgemaster's Charm deals X damage to target creature.
• Destroy X target artifacts.
• Create an X/X colorless Juggernaut artifact creature token.

Search your library for an Equipment card, reveal it, put it into your hand, then shuffle.

{T}, Sacrifice Forgewatcher: Add two mana of any one color. If that mana is spent on a creature spell, it gains haste until end of turn.

Equipped creature has first strike.
{R}: Equipped creature gets +1/+0 until end of turn.
Equip {2}

Whenever Forgotten King's Mask enters or equipped creature dies, attach it to target creature you control.
Equipped creature has base power and toughness 5/5 and is a Noble in addition to its other types.
{1}{R}, Discard two cards: Create a 1/1 white Human creature token and attach Forgotten King's Mask to it. Activate only as a sorcery.

Flying
Disgraced 4 (This enters with four -1/-1 counters. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)
Whenever you put one or more -1/-1 counters on Forgotten Tyrant, it deals that much damage to any target.