msem-instigator

Flying
When Delivery Bird enters, if you control an artifact, put a +1/+1 counter on another creature you control.

Lifelink
Sacrifice Devoted Apothecary: Remove a counter from target permanent.

Diligent Believer gets +1/+1 for each +1/+1 counter on other creatures you control.

When Doomed Traveler dies, create a 1/1 white Spirit creature token with flying.

When Dynasty Infantry enters, choose one —
• Search your library for a card named Dynasty Infantry, reveal it, put it into your hand, then shuffle.
• Put a +1/+1 counter on target creature you control.

When Eighth-Life Companion enters, put two +1/+1 counters on target creature you control.
Recite {1}{W} (You may cast this from your graveyard for its recite cost. If you do, exile it when it enters or if it would leave.)
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.)

Double strike
Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)

Flying
When Ephara's Watcher enters, scry 2.

Flying, lifelink

When Escorted Ambassador enters, create two 1/1 white Robot Soldier artifact creature tokens.
Whenever a nonland, nontoken permanent enters, exile it unless it was the first to enter under its controller's control this turn.

Flying (This creature can't be blocked except by creatures with flying or reach.)
Escorted Rider gets +1/+1 as long as you control another creature with flying.

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)
Creature tokens you control have lifelink.

Vigilance
When Expendable Victim dies, create a 1/1 colorless Construct Actor creature token.

Whenever another Avatar you control enters, upgrade it and Experienced Mentor. (Give each one of the listed counters it doesn't already have. Upgrades are independent.)
• +1/+1
• First strike
• Vigilance

Whenever you gain life, put a +1/+1 counter on Faithful Acolyte.
Faithful Acolyte has lifelink as long as it has four or more +1/+1 counters on it.

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.