msem-instigator

Flash
Flying
Whenever another Spirit you control enters, put a +1/+1 counter on Flickers in the Night.

Heroic — Whenever you cast a spell that targets Floodspeaker Triton, put a +1/+1 counter on Floodspeaker Triton, then scry 1.

Flying
Menagerie — At the beginning of combat on your turn, if there are five or more creature types among creatures you control, create a 1/1 black Insect Spirit creature token with flying and you gain 1 life.

Whenever an Aura you control enters, draw a card.

Flying
Whenever Flying Scorpion attacks, it gets +1/+0 until end of turn for each creature you control that's not attacking.

Sacrifice a creature: Harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Look at the top two cards of your library. Put any number of them into your graveyard and the rest back on top in any order.

Flying
Whenever a creature you control attacks, you gain 1 life.

Once each turn, when you activate a nonmana ability, you may tap target creature.
{1}{U}: Foggy Town Militia gains flying until end of turn.

Noncreature spells you cast cost {1} more to cast.
Noncreature spells your opponents cast cost {1} more to cast unless that player controls more creatures than you.

Improve {R} ({R}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Whenever another creature you control with power less than or equal to Folkvar, Galdurheim Brawler's power attacks, Folkvar deals 1 damage to the player or planeswalker that creature is attacking and you gain 1 life.

Whenever a Plains you control enters, create a 1/1 white Soldier creature token.
Whenever you attack, you may search your library for a Plains card, reveal it, put it into your hand, then shuffle.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
{U}{R}, Exile an instant or sorcery card from your graveyard: Foolhardy Huo gains flying and first strike until end of turn.

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.

Hexproof

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.

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.

{W}{W}, Exile a legendary creature card from your graveyard: If Forgotten Heir is a Peasant, it becomes a Human Noble Knight with base power and toughness 3/3, lifelink, and vigilance.

{B}{R}, Sacrifice a creature: Create a token that's a copy of Forlorn Companion, except it has no mana cost.

When Forlorn Farmhand dies, create a 1/1 colorless Spirit creature token.

Hexproof
Whenever you cast a spell with mana value 5 or greater, each opponent discards a card and loses 3 life.

Flying
Mark (Whenever this creature attacks, mark target creature until end of turn.)
Whenever a marked creature dies, you gain 2 life.

Flying
Whenever a creature in Forsaken Soulherd's pack dies, look at the top card of your library. If it's a creature card with equal or lesser power, you may reveal it and put it into your hand. If you didn't put that card into your hand, you may mill it. (Two or more creatures you control with equal power are in a pack.)

When Forserval enters, creatures you control get +1/+1 and gain haste until end of turn.

Bulwark — At the beginning of each upkeep, if you control a creature with toughness 4 or greater, Fortress Sentinel gains hexproof until end of turn.

At the beginning of each combat, target creature you control gets +3/+3 until end of turn.
Revive {2}{B}{R}{G} ({2}{B}{R}{G}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost. Activate this ability only any time you could cast a sorcery.)