msem-instigator

Vigilance
Whenever Watchful Navigator crews a Vehicle, that Vehicle gets +1/+1 and gains vigilance until end of turn.

Whenever a creature in Water Sutra Daoshi's pack dies, return a creature card with lesser mana value than that creature from your graveyard to your hand. (Two or more creatures you control with equal power are in a pack.)

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
{3}{U}: Target creature gains slipstream until end of turn.

Prowess
Whenever you cast a noncreature spell, target creature can't block this turn.

Survivors you control have double strike.

When Weald Wanderer enters, you gain 3 life and each opponent loses 2 life.
{1}, Pay 1 life: Shuffle Weald Wanderer into its owner's library. If you do, draw a card.

When Weary Adventurer enters, return a permanent you control to its owner's hand.

When Weathered Pilgrim enters, return target card from your graveyard to your hand.

Whenever Weathered Skiff attacks, it gets +1/+1 until end of turn.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Ship Vehicle becomes an artifact creature until end of turn.)

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
When Weathered Veteran dies, you may put a -1/-1 counter on target creature.

This spell costs {1} less to cast for each creature you control that attacked this turn.
First strike
Whenever Weavetide Militia and at least one other creature attack, creatures you control get +1/+0 until end of turn.

When Weizenmother enters, return target creature card with mana value 3 or less from your graveyard to the battlefield.
Plainscycling {2} ({2}, Discard this card: Search your library for a Plains card, reveal it, put it into your hand, then shuffle.)

Advance {5}{B}{B} (Cast this for {5}{B}{B} to advance it as it enters. {5}{B}{B}: Advance this as a sorcery.)
Whenever Well-Oiled Sniper advances, target creature gets -3/-3 until end of turn.

Whenever West Ward Purifier becomes tapped, you gain 1 life.

Flash
Heretic (Whenever you cast a spell that doesn't share a color with this creature, it gets +1/+1 until end of turn.)

When Whisper Witch enters, choose up to one target creature. That creature's controller mills four cards, then puts that creature on top of their library.

When Whistling Blades enters, you may destroy target creature or planeswalker.
Recite {1}{B}{B} (You may cast this creature from your graveyard for its recite cost. If you do, exile it when it enters or if it would leave the battlefield.)

Vigilance

When Wild Entourage enters, create two 1/1 colorless Construct Actor creature tokens.
{4}{G}: Wild Entourage gets +2/+2 and gains trample until end of turn.

When Wild Hermit dies, create a 2/2 white Cat creature token.
Revive—{3}{G}{G}, Sacrifice a creature. ({3}{G}{G}, Sacrifice a creature, 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.)

Colossal 4—{5}{G} (You may cast this for its colossal cost to have it enter with four +1/+1 counters; or pay {5}{G} as a sorcery: Put four +1/+1 counters on it if it has none.)
Trample

Assault {2}{G} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Wildborn Marauder assaults, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Harmony — You may pay {1}{G}. If you do, create a 3/3 green Beast creature token.
When Wildheart Chorister enters, harmonize. (Trigger up to one harmony of a permanent you control.)

When Wildsong Summoner enters, shuffle your library, then reveal cards from the top until you reveal a permanent card. Create a token that's a copy of that card, except it's a 3/3 green Beast creature. Put all cards revealed this way on the bottom of your library in a random order.