msem-instigator

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.)

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.)
Return each nonland permanent your opponents control to its owner's hand.

Whenever two or more creatures you control deal combat damage to a player, you lose 1 life and draw a card.

Return target card from your graveyard to your hand.
{1}{G}, Tap an untapped Shaman you control, Exile Whisper of the Wild from your graveyard: Return target card from your graveyard to your hand.

Whispering Canal enters tapped unless you control a basic land.
{T}: Add {U} or {B}.

Whenever an opponent casts a spell, that player mills X cards, where X is that spell's mana value.

Mill three cards. When you do, return another nonland card from your graveyard to your hand.

Flying, haste
When Whisperwoods Phoenix dies or you discard it, create a red enchantment token named Ash with “Whenever you cast a noncreature spell, put a feather counter on this. Then if there are three or more feather counters on it, sacrifice it and return a card named Whisperwoods Phoenix from your graveyard to the battlefield.”

When Whisperwoods Reclaimer enters, if there are three or more land cards in your graveyard, return target land card from your graveyard to the battlefield tapped.

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.)

Double strike

{T}: Add {C}.
{T}: Each opponent may draw a card. For each player who does, draw a card.

Improve {1} ({1}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Other creatures you control have improve {1}.

Escalate {B} (Pay this cost for each mode chosen beyond the first.)
Choose one or more —
• Wicked Blow deals 3 damage to target player or planeswalker.
• Wicked Blow deals 3 damage to target creature.
• You gain 3 life.

When Wiedfree Investigator enters, return up to one target artifact card with mana value 2 or less from your graveyard to the battlefield.
{2}, Sacrifice an artifact: Draw a card.

Whenever a player casts an instant or sorcery spell, Wiedfree Roughrider deals 2 damage to that player.
Whenever Wiedfree Roughrider attacks, you may pay {X}. When you do, destroy target noncreature, nonland permanent with mana value X.

Whenever Wild Bearmaster attacks, each other attacking creature you control gets +X/+X until end of turn, where X is Wild Bearmaster's power.

Whenever Wild Dogs of the Night or another Horror you control enters, exile up to one target card in a graveyard. If that card was a creature card, you gain 2 life and put two +1/+1 counters on that Horror.

You may put a creature or planeswalker card from your hand onto the battlefield. It gains haste. Sacrifice it at the beginning of the next end step. Whenever an ability of that permanent is activated this turn, you may copy that ability. You may choose new targets for the copy.

When Wild Festivities enters or at the beginning of your upkeep, you may put a creature card from your hand onto the battlefield. If you do, each opponent creates a 1/1 blue Frog creature token.

Gain control of target land.

Erratic (When this creature dies, reveal the top four cards of your library. Put a creature card that costs less than this revealed this way onto the battlefield and the rest on the bottom of your library in any order.)
When Wild Gravetender enters, you gain 2 life for each creature card in your graveyard.
{1}{G}, Sacrifice a creature: Return Wild Gravetender from your graveyard to your hand.

As an additional cost to cast this spell, you may tap two untapped creatures you control.
Search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle. If you tapped two creatures as you cast this spell, create a token that's a copy of that creature, except the token isn't legendary if the creature is legendary.

Riot (This creature enters with your choice of a +1/+1 counter or haste.)
Whenever Wild Lifescale attacks, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.
Inscribe {2}{R}{R} ({2}{R}{R}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)