msem-instigator

Creatures you control with flying get +1/+1.

When Fearless Realmwalker enters, put a +1/+1 counter on each of up to two target creatures.
Whenever Fearless Realmwalker attacks, you may pay {2}{W}. If you do, aetherize it. (To aetherize, create a token that's a copy of it, then exile that token.)

Battalion — Whenever Fearsome Army and at least two other creatures attack, creatures you control gain menace until end of turn.

Reach
Once each turn, when a creature you control dies, you may draw a card.

Return target spell or creature to its owner's hand. If you controlled that spell or creature, catalyze. (The next spell you cast this turn costs {1} less to cast.)

Feed to the Pigs deals X damage to any target. You gain X life.

Whenever an attacking creature dies, you may pay {R}. If you do, create a 2/1 red Merfolk creature token.

Flying
At the beginning of your upkeep, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Enchant creature
When Feline Furor enters, it deals 2 damage to enchanted creature.
Enchanted creature gets +2/+0 and has menace.

Destroy target creature with power 4 or greater.
Create two Idol tokens. (They're artifacts with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Equipment spells you cast cost {1} less to cast.
Armed — As long as Fellor Armorsmith is equipped, equip abilities you control cost {1} less to activate.

Choose one—
• Fellor Charm deals 3 damage to any target.
• Target creature gains lifelink and indestructible until end of turn.
• Attacking creatures get +1/+1 until end of turn.

When Fellor Ironborn enters, you may return target artifact card from your graveyard to the battlefield. If it's an Equipment, you may attach it to target creature you control.

Fellor Vanguard gets +1/+1 as long as you control a Mountain.
{1}{R}: Fellor Vanguard gets +1/+0 until end of turn.

Lifelink
Deploy 3 (As this enters, you may tap any number of other creatures you control with total power 3 or more.)
When Fellow Traveler enters deployed, you and target opponent each draw two cards.

Menace
As long as you control exactly one other creature, that creature gets +1/+1 and has menace.

Menace
When Fenhauler Gang enters, each player mills three cards.
Whenever Fenhauler Gang deals combat damage to a player, return up to one target creature or land card from your graveyard to your hand.

Equipped creature gets +3/+0.
Whenever a creature you control attacks and isn't blocked, you may pay {4}. If you do, attach Feral Cleaver to that creature.
Equip {3}

Colossal 3—{4}{R}{G} (You may cast this for its colossal cost to have it enter with three +1/+1 counters; or pay {4}{R}{G} as a sorcery: Put three +1/+1 counters on it if it has none.)
Each creature you control with a counter on it can't be blocked by more than one creature.

Ferocious Flame deals 2 damage to any target. If you control a creature with power 4 or greater, it deals 4 damage instead.

When Ferocity of the Redeemed enters, return up to two target creature cards with mana value 1 or less from your graveyard to the battlefield.
Revive {2}{W}{W} ({2}{W}{W}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Whenever a permanent with one or more counters on it is put into your graveyard from the battlefield, it deals that much damage to any target and you gain that much life.

At the beginning of your upkeep, exile the top card of your library. Until end of turn, you may play that card if it's an instant or sorcery card.

Attacking creatures you control get +1/+0.

{2}{R}{R}, Exile an instant or sorcery card from your graveyard: Fervid Dragonheart gets +1/+2, gains flying, and becomes a Dragon until end of turn.