msem-instigator

If Wandering Domovoi would be dealt noncombat damage, prevent that damage and put three +1/+1 counters on Wandering Domovoi instead.

Wary Rider has first strike as long as its attacking.
Wary Rider gets +1/+0 as long as you control two or more other creatures.

Flying, lifelink
At the beginning of each end step, if you gained 3 or more life this turn, choose one —
• Put a +1/+1 counter on Waxing Angel.
• Exile target artifact or enchantment.

Flying
Whenever Wind Savant attacks, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Wind Savant gets +1/+1 until end of turn.

Flying
Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
As long as Wings of Trust has three or more +1/+1 counters on it, it has lifelink and vigilance.

Harmony — Germinate. (Put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)
When Woopip Chef enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Vigilance
When Worn Peacekeeper dies, create a 1/1 white Soldier creature token with vigilance.

Whenever a nontoken creature you control enters, if it wasn't cast, put a +1/+1 counter on Wretched Skulker.
{3}{W}, Sacrifice Wretched Skulker: Exile target nonland permanent with mana value less than Wretched Skulker's power.

Flying
When Yujei enters, create a 1/1 white Bird creature token with flying.
{2}{W}: Put a +1/+1 counter on another target creature. It gains flying until end of turn. If it already has flying, put a +1/+1 counter on Yujei instead.

Whenever another creature you control leaves the battlefield, put a +1/+1 counter on Zealot of Mahara.
Surpass {5}{W} ({5}{W}: Transform this creature. This costs {1} less to activate for each counter on it. Activate only as a sorcery.)

When Zhedina Envoys leaves the battlefield, create two 1/1 Scout creature tokens that are all colors.

Converge — Admin of Asthenia enters with a +1/+1 counter on it for each color of mana spent to cast it.
Admin of Asthenia can't attack unless its power is 4 or greater.

Whenever you make first contact, you may draw a card. If you do, put a card from your hand on the bottom of your library. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

Flash
When Agent of Deception enters, counter target creature or planeswalker spell unless its controller pays {X}, where X is your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Flying
Whenever a creature enters under an opponent's control, you may pay {1}{B}. If you do, fateseal 1. (Look at the top one cards of an opponent's library, then put any number on the bottom and the rest on top in any order.)

Whenever Almgrove Ambassador blocks or becomes blocked, you may untap target creature and remove it from combat.

When Ancestral Council enters, search your library for an instant or sorcery card with mana value 2 or less, reveal it, put it into your hand, then shuffle.

Flash
Flying
At the beginning of each end step, if two or more spells were cast this turn, you may draw a card. If you do, discard a card.

Flying
Improve {1}{U} ({1}{U}: 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.)

When Bearer of Silk Chains enters, gain control of target nonland permanent until Bearer of Silk Chains leaves the battlefield. If that permanent is a Horror, gain control of it instead.

{T}: Until end of turn, target land is every basic land type in addition to its other types and its name becomes Morphic Sea.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Sacrifice Bonetooth Darter: Counter target instant, planeswalker, or sorcery spell unless its controller pays {1}.

Flying

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Concord — As long as there are four or more card types among permanents you control, Bubbledome Waveblade gets +1/+1.

Artifact spells you cast cost {1} less to cast.
The first ability of an artifact you activate each turn costs {1} less.