msem-instigator

Whenever one or more other creatures you control enter, you gain 1 life. If at least one of those creatures was a Cleric, you gain 2 life instead.
As long as you have at least 8 life more than your starting life total, other Clerics you control get +1/+1.

Flying, lifelink

First strike
When Faradia's Collector enters, if an opponent controls more lands than you, create a colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.”

Tithe (As you cast this spell, you may tap three artifacts and/or creatures you control.)
Creatures can't attack this turn. If this spell's tithe was paid, opponents can't cast spells this turn.

Flying, vigilance, indestructible
Faradia, Honored Sovereign can't attack or block unless you tap three other untapped creatures and/or artifacts you control.

{1}{W}, {T}: Aetherize target creature you control. (To aetherize, create a token that's a copy of it, then exile that token.)

Enchantment spells you cast cost {1} less to cast.

Enchant creature
Embody (Enchanted creature is a copy of this card except for its types.)
Whenever Fate of the Devout becomes tapped, it gets +1/+1 until end of turn.

Destroy all nontoken creatures.

When Fateshifter's Prophet enters, you gain 2 life and scry 2.

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.

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

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.

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.

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

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.

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