msem-instigator

Creatures you control get +1/+0 and attack each turn if able.
As long as you control four or more Mountains, attacking creatures you control get an additional +1/+0 and have first strike.

You may put a Dragon creature card from your hand onto the battlefield. That creature gains haste until end of turn. Return it to its owner's hand at the beginning of the next end step.

Advance {3} (Cast this for {3} to advance it as it enters. {3}: Advance this as a sorcery.)
Whenever Wastes Scrambler advances, put your choice of a +1/+1, first strike, menace, trample, or vigilance counter on it. If {R}{W}{B} was spent to advance it, repeat this process twice.
Crew 1

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.

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

Target player mills two cards.
Draw a card.
Coalesce {6}{U} (You may cast this from your graveyard for {6}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

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.)

{T}, Pay 1 life, Sacrifice Wayfarer's Shrine: Search your library for a basic land card, put it onto the battlefield, then shuffle.

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.