msem-instigator

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

Menace (This creature can't be blocked except by two or more creatures.)

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.

Prowess, haste
Mirage {R} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

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

Whenever Whitepeak Channeler deals combat damage to a creature, tap that creature. That creature doesn't untap during its controller's next untap step.

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.)

{T}: Add {C}.
{9}, {T}, Exile Whiterun Gates: Take an extra turn after this one.

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

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.)

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}.

{2}, Sacrifice Wicked Fossil: Target player loses 2 life and you gain 2 life.
{2}{B}{B}: Return Wicked Fossil from your graveyard to the battlefield transformed. Activate only during your turn.

You may exert Wiedfree Behemoth as it attacks. When you do, it gets +3/+3 and gains trample until end of turn. (An exerted creature won't untap during your next untap step.)

You may exert Wiedfree Berserker as it attacks. When you do, target creature can't block this turn. (An exerted creature won't untap during your next untap step.)
If exerting a creature you control causes a triggered ability of a permanent you control to trigger, that ability triggers another time.

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.

Voracious 1 (As this enters, you may sacrifice an artifact or creature. If you do, it enters with a +1/+1 counter on it.)
Vigilance, reach

Menace
Whenever Wightclaw deals combat damage to a player, that player discards a card and you draw a card.

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 one or more creatures you control attack, you may post a bounty on target creature. (Put a bounty counter on that creature. It has “When this creature dies, each opponent draws a card” as long as it has a bounty counter on it.)