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.

{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.

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

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

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

When Fidelity of the Pure dies, create a 1/1 green and white Elk Spirit creature token.
Revive {2}{W} ({2}{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.)

When Folded Fan Recruit enters, invigorate 1. (Choose a creature with the least power among creatures you control and put a +1/+1 counter on it.)

Improve {W} ({W}: 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 Frontier Wayfinder attacks, untap each other creature you control.

Flying
Whenever an artifact you control enters, put a +1/+1 counter on Glorious Wingwright. This ability triggers only once each turn.

Golden Company Valiant can block any number of creatures.
At the beginning of combat on each opponent's turn, Golden Company Valiant gets +1/+1 until end of turn for each creature that player controls.

When Greypelt Clergy enters, choose one —
• Put a +1/+1 counter on Greypelt Clergy.
• Permutate. (You may remove a counter from a creature you control. If you do, put two +1/+1 counters on a different creature you control.)

Whenever another Hound you control enters, put a +1/+1 counter on Greypelt Initiate.

Flying, lifelink

Lifelink
Whenever you cast a spell with mana value 2 or less, put a +1/+1 counter on Hallowed Moon Sentinel.

Whenever you cast an enchantment spell, you may pay {W}. If you do, put a +1/+1 counter on target creature.

Whenever another nontoken permanent you control enters, create a Food token.
At the beginning of each end step, put X +1/+1 counters on up to one target creature, where X is the amount of life you've gained this turn.

When Haunted Hermit enters, choose one —
• Put a +1/+1 counter on Haunted Hermit.
• Create a 1/1 white Spirit creature token with flying.

Flying
When Heaven's Eyes enters, create a 1/1 white Bird creature token with flying. Then you gain 1 life for each creature in Heaven's Eyes's pack. (Two or more creatures you control with equal power are in a pack.)

Flying (This creature can't be blocked except by creatures with flying or reach.)
Heavensent Emissary enters with a +1/+1 counter on it for each other creature with flying you control.

Flying
{2}{W}, Sacrifice Herald of the Departed: Create two 1/1 white Spirit creature tokens with flying.

Encourage ({T}: Another target creature you control gets +1/+1 until end of turn. Encourage only as a sorcery.)
Whenever a creature deals combat damage to a player, if it was encouraged by Herald of the White Orchid this turn, create a 1/1 white Soldier creature token.

At the beginning of your upkeep, nourish 1. (To nourish 1, either put a +1/+1 counter on this creature or create a 1/1 white Citizen creature token.)

When Hinasa Historian enters, create a 2/2 colorless Spirit creature token.
Whenever a colorless creature you control enters, you gain 1 life.

{T}: Untap another target enchanted creature you control. You may attach target Aura attached to that creature to another creature you control. Activate only as a sorcery.