msem-instigator

Trample, haste
Defiance (Whenever this creature takes damage, if it survives and wasn't defiant, put a +1/+1 counter on it and it becomes defiant.)
Whenever Wastewolf attacks, it deals 1 damage to any other target.

Whenever Wasting Soul attacks or blocks, sacrifice a creature, then put two +1/+1 counters on Wasting Soul.

Whenever Watch Me Burn enters or another source you control deals noncombat damage, put an ignition counter on Watch Me Burn. Then it deals damage equal to the number of ignition counters on it to each opponent.

Creature tokens you control have vigilance.
Whenever Watch of the Dead or another enchantment you control enters, create a 2/2 black Zombie creature token.

Flying
Whenever a nontoken, noncreature, nonland permanent you control enters, create a token that's a copy of that permanent except it has no mana cost and it isn't legendary.

Changeling (This card is every creature type.)
Watcher of the Polyps has all names of creature cards in addition to its name as long as it's on the battlefield.
Watcher of the Polyps gets +X/+X, where X is the greatest number of creatures you control with the same name.

Vigilance
Bulwark — {1}{W}, {T}: Create a 1/1 white Soldier creature token. Activate only if you control a creature with toughness 4 or greater.

Menace
Whenever one or more cards leave your graveyard or Watchers of the Veil leaves your graveyard, you may draw a card. If you do, discard a card.

Flying
{1}{W}, {T}: Tap target creature.

Vigilance, reach
Watchful Authority can block an additional creature each combat.

Flying

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

Vigilance
Whenever you cast a noncreature spell, you gain 2 life.

Flying (This creature can't be blocked except by creatures with flying or reach.)
Vigilance (Attacking doesn't cause this creature to tap.)

Whenever Watchkeeper Deserter attacks, discard up to two cards, then draw that many cards. Watchkeeper Deserter gets +X/+0 until end of turn, where X is the total mana value of the discarded cards.

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.)

Waterfront Market enters tapped unless you control a basic land.
{T}: Add {W} or {U}.

Each other creature you control that's a Merfolk or an Elemental gets +1/+1.
Whenever you cast an instant, sorcery, or Merfolk spell, you may pay {1}. If you do, create a 1/0 blue Elemental creature token.

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.

When Wavebreaker enters, add two mana of any one color. You can't spend this mana to cast spells.

Whenever Wavering Sorcerer attacks, you may switch its power and toughness until end of turn.
Unveil {3}{U}{R} ({3}{U}{R}: Transform this. Unveil only as a sorcery.)

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 another creature you control enters, you may have Waxing Celestial get +1/+1 until end of turn.

Equipped creature gets +2/+2 and has vigilance.
Equip {4}
Wanderlust — Wayfarer's Adornments has equip {0} as long as you control four or more differently named lands.