msem-instigator

If a source would deal damage to a creature this turn, prevent all but 1 of that damage.

Whenever you attack or block with one or more other creatures, Wehre-District Patrollers gets +1/+0 and gains first strike until end of turn.

Enchant creature
Enchanted creature gets +2/+2 as long as it's legendary. Otherwise, it can't attack or block.
When enchanted creature dies, if it's legendary, return that card to its owner's hand.

Enchant creature
Enchanted creature has flying.
{2}: Tap enchanted creature.

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

Flash
Whenever Whimsical Dancer enters or is exerted, target creature gets +1/+0 and gains first strike until end of turn.
You may exert Whimsical Dancer as it attacks. (An exerted creature won't untap during your next untap step.)

Flying, lifelink
Creatures entering or leaving the battlefield don't cause abilities to trigger unless that creature is in a pack. (Two or more creatures a player controls with equal power are in a pack.)

Create a 1/1 white Spirit creature token with flying.
Whenever a nontoken creature you control dies, you may pay {W} and exile Whispered Wishes from your graveyard. If you do, create a 1/1 white Spirit creature token with flying.

Double strike

Vigilance

Alpha (You may have this creature enter with a +1/+1 counter on it. If you do, it becomes alpha and can only attack alone.)

When Whiterun Ordainer enters, you gain 4 life.

Flying (This creature can't be blocked except by creatures with flying or reach.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

When Wilderness Forager enters, you may reappropriate. If you do, gain 6 life. Otherwise, gain 3 life. (To reappropriate, exile exactly two cards from your hand and/or graveyard.)

Create two 1/1 colorless Samurai creature token. Those creatures gain first strike until end of turn.

Create a 1/1 green and white Mouse Soldier creature token with vigilance and a 1/1 white and black Badger Cleric creature token with lifelink.

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
Windwatch Eagle has vigilance as long as it has a +1/+1 counter on it.

Flying
Windwise Courier has indestructible as long as you've revealed a card from your hand this 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.

Armed — Winterborn Savage gets +1/+1 and has vigilance as long as it's equipped.

Harness (You may tap a creature you control as you cast this spell. If you do, reduce this spell's mana cost by that creature's power.)
You gain X life.

Witchseeker Mob's power and toughness are each equal to twice the number of Citizens and/or Peasants you control.
When Witchseeker Mob enters, exile target nonland permanent an opponent controls with mana value less than or equal to Witchseeker Mob's power until Witchseeker Mob leaves the battlefield.

Destroy all non-Horror creatures.
Coalesce {8}{W}{W} (You may cast this from your graveyard for {8}{W}{W}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)