msem-instigator

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

Put target nonland permanent on top of its owner's library.

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.

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.

Spend only black mana on X.
Up to two target creatures each get -X/-X until end of turn. You gain X life.

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.

Create two Idol tokens, then counter target spell unless its controller pays {1} for each Idol you control. (They're artifacts with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Counter up to one target spell unless its controller pays {2}. Until end of turn, you may cast spells as though they had flash.

Exile all Inscription cards from your graveyard and all exiled Inscription cards you own. For each card exiled this way, you may inscribe it onto a creature you control. (Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost.)

Survivors you control have double strike.

At the beginning of your upkeep, each player draws a card.

Target creature gets +2/+2 until end of turn.
Wanderlust — If you control four or more differently named lands, that creature gets +4/+4 until end of turn instead.

When Weald Sentry enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
When Weald Sentry dies, draw a card.

Mill five cards, then return up to one permanent card from your graveyard to your hand.

Until end of turn, target noncreature, non-Equipment artifact becomes an Equipment with equip X and “Equipped creature gets +X/+0”, where X is that artifact's mana value.

Weathered Fortress enters tapped.
{T}: Add {U} or {R}.
{U}{R}: Until end of turn, Weathered Fortress becomes a 1/4 blue and red Golem creature with with “When this creature attacks, switch its power and toughness until end of turn” and “Whenever this creature attacks or blocks, torment yourself.” It's still a land. (To torment yourself, lose 3 life unless you discard a card or sacrifice a nonland permanent.)

When Weaver of Mists enters, substantiate target card in your graveyard. (Put it onto the battlefield face down as a 2/2 creature. You may turn it face up and cast it at any time for its mana cost if it isn't a creature.)
Spells you cast from anywhere other than your hand cost {1} less to cast.

Vision (Whenever this or another creature you control enters, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Weaver of the Winds envisions an instant or sorcery card, draw a card.

At the beginning of your upkeep, discard a card and create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Weeping Lotus enters with five petal counters on it.
At the beginning of your upkeep, remove a petal counter from Weeping Lotus. If you do, create a colorless artifact token named Lotus Petal with “{T}, Sacrifice this artifact: Add one mana of any color.”

Choose any number —
• Each player loses X life.
• Each player discards X cards.
• Each player sacrifices X creatures.
• Each player sacrifices X lands.