msem-instigator

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.)

When Fearless Recruit dies, create a 1/1 white Rebel creature token.

This spell can't be countered.
Ward {3}
{W}, Exile Fearsome Xenoblossom from your graveyard: You gain 4 life.

Whenever you cast a spell that doesn't share a color with Feathered Warden, you may gain 1 life.

When Featherfall Ascetic enters, create a 1/1 white and blue Bird creature token with flying.
Whenever a nontoken Aura enters enchanting Featherfall Ascetic, for each other creature you control, you may create a token that's a copy of that Aura enchanting that creature.

Flying, first strike, lifelink

Put a +1/+1 counter on target creature, then you gain 1 life for each +1/+1 counter among creatures you control.

When Fel Alston, Halfway Queen enters, return target creature card from your graveyard to the battlefield. Then exile that creature unless Fel Alston was cast for its escape cost.
Escape—{1}{W}{U}{B}, Sacrifice two creatures. (You may cast this card from your graveyard for its escape cost.)

Exile X target permanents you control. Return them to the battlefield under your control at the beginning of the next end step.
Draw a card.

Archive 5 (As this enters, shuffle the top five cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
Whenever a permanent card is put into your graveyard from the battlefield, you may put that card on the bottom of the archived library.

[+2]: Each player can cast only one more spell until your next turn.
[–3]: Exile all other permanents, then return them to the battlefield tapped under their owner's control. Creatures can't attack you or planeswalkers you control until your next turn.
[–8]: Return all permanent cards from your graveyard to the battlefield tapped.

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.”)

Each player chooses a creature with the least power among creatures they control. Then destroy the rest.

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.

Battalion — Whenever Fellor Bloodseeker and at least two other creatures attack, Fellor Bloodseeker gains lifelink until end of turn.

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.

Armed — Fellor Elite has double strike as long as it's equipped.

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.

Haste
Battalion — Whenever Fellor Tactician and at least two other creatures attack, creatures you control get +1/+1 until end of turn.

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.

{R}{W}, {T}: Femourri Archer deals damage equal to its power to any target. You gain that much life.

Double strike
When Fencing Tutor enters, create a 0/1 white Soldier creature token with double strike.

[+1]: Until your next turn, whenever up to one target permanent deals damage to another permanent or player, it deals that much damage to itself.
[–X]: When you next cast a noncreature spell with mana value X or less this turn, copy it. You may choose new targets for the copy.
[–2]: Create an X/X blue Spirit creature token, where X is the number of colors of mana you've spent to cast spells this turn.

Fennec Fostress gets +1/+0 for each Aura you control.