msem-instigator

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.)

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.

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

Wildfire Elemental has frenzy 4 as long as you control no other creatures. (Whenever this creature attacks and isn't blocked, it gets +4/+0 until end of turn.)
Wildfire Elemental has frenzy 4 as long as you have no cards in hand.

Vigilance, reach
When Winter Widow enters, you may destroy target creature with flying.

Enchantments you control have hexproof.
Wira Inti, Skyfather can't attack or block unless you control five or more enchantments.
At the beginning of combat on your turn, up to two other target enchantments you control each become a creature in addition to their other types and have flying, vigilance, and base power and toughness 4/4.

Whenever Witchfinder Artur enters or attacks, each opponent mills two cards and loses 2 life.
Whenever you cast an instant or sorcery spell, you may exile target instant or sorcery card with mana value less than that spell's mana value from an opponent's graveyard. If you do, cast a copy of the exiled card without paying its mana cost.

Deathtouch
Whenever Withered Elk deals combat damage to a player, that player loses half their life, rounded down.

This spell costs {1} less to cast if you have more life than an opponent and {1} less to cast if you control a Cleric.
Deathtouch

Destroy all non-Horror creatures.
Coalesce {8}{W}{W} (You may cast this from your graveyard for {8}{W}{W}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Each player shuffles their hand and each non-Revelation card from their graveyard into their library, then draws seven cards. You may put any number of land cards from your hand onto the battlefield.
Coalesce {6}{G}{U}{U} (You may cast this from your graveyard for {6}{G}{U}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

When this permanent transforms into Worthy Vulpine or at the beginning of combat on your turn, creatures you control gain haste and trample until end of turn.

Trample
Whenever Wun Su, Guru of the Staff deals combat to a player, you may create Wun Su's Staff, a legendary colorless Equipment artifact token with “Equipped creature gets +5/+5” and equip {5}, then attach it to Wun Su.

Flying
{2}: Copy target activated or triggered ability you control. You may choose new targets for the copy.
{W}{U}{B}{R}{G}: Search your library for a card, exile it, then shuffle. Until the end of your next turn, you may play that card.

Trample, vigilance
Spells your opponents cast that target Xiejuan and Hao Lu cost {X} more to cast, where X is the number of other creatures you control.
Whenever another creature you control dies, draw a card.

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.)
When Xiejuan, the Regal Beast becomes alpha, draw a card for each other creature you control.

Flash
This spell can't be countered.
When Xing, the Lucky Charm enters, draw three cards.
{U}{R}, Discard three cards: Return Xing from your graveyard to your hand.

{R}: Xiyue Dragondancer gets +1/+0 until end of turn.
Whenever you cycle Xiyue Dragondancer or it attacks, create a Treasure token.
Basic landcycling {1}{R} ({1}{R}, Discard this card: Search your library for a basic land card, reveal it, and put it into your hand, then shuffle.)

Flying, trample
Once during each of your turns, you may cast a spell from your graveyard without paying its mana cost.
When Yhzag, Alpha and Omega is put into a graveyard from anywhere, its owner shuffles their graveyard into their library.

Whenever Yrodu, the Lotus Ablaze attacks, eight target permanents don't untap during their controller's next untap step.
Whenever Yrodu blocks a creature, destroy that creature at end of combat.

This spell costs {1} less to cast for each creature that died this turn.
At the beginning of your upkeep, put target creature card from a graveyard onto the battlefield under your control.
{1}, Sacrifice another creature: Zarad, the Final Adversary gains indestructible until end of turn.

Flying
When Zenith of Greed enters, search your library for up to two cards named Treasure Hoard and put them onto the battlefield, then shuffle.

Flash
Defender, flying