msem-instigator

Defender
When Wall of Rime enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

When Wandering Visionary enters the battlefield, draw a card.
{W}{U}{B}{R}{G}: Create a 1/1 blue Elemental creature token with flying.

Vanishing 1 (This creature enters the battlefield with a time counter on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When Waning Behemoth enters the battlefield, you may pay {X}. If you do, put X time counters on it.

When War of Resources enters the battlefield, recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)
Whenever a creature you control dies, each opponent loses 1 life.

Protection from instants and from sorceries
When Warbringer Titan enters the battlefield or attacks, create two 1/1 white Soldier creature tokens with melee. (Whenever that creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)

When Ward-Lost Hermit enters the battlefield, mill three cards.
{2}, {T}, Sacrifice Ward-Lost Hermit: Return target instant or sorcery card from your graveyard to your hand.

When Warden of Rehis-Dorahn enters the battlefield, put a -1/-1 counter on each creature.
{2}{B}{G}, {T}: Destroy target creature with a counter on it.

Flying, vigilance
When Warden of Seas enters the battlefield, tap all other creatures.
Each opponent can't untap more than one nonland permanent during each of their untap steps.

Defender
When Warden of Silence enters the battlefield, draw a card.

When Warden of the Archives enters the battlefield, if you cast it, tap up to four target permanents.

When Warden of the Dead enters the battlefield, you draw a card and you lose 1 life.
When Warden of the Dead dies, conjure three cards named Warden of the Dead and shuffle them into your main library. For the rest of the game, you may cast spells named Warden of the Dead without paying their mana costs.

When Warfan of Changing Winds enters the battlefield, draw a card.
Whenever a card you own is exiled from anywhere, you may put it on the bottom of your library.

Enchant creature
When Warrior's Discipline enters the battlefield, put a +1/+1 counter on enchanted creature.
Whenever enchanted creature deals combat damage to a player, double the number of +1/+1 counters on it.

When Warrior's Perspective enters the battlefield, invigorate 1. (Choose a creature with the least power among creatures you control and put a +1/+1 counter on it.)
Whenever a creature you control with a +1/+1 counter on it becomes tapped, you may draw a card. If you do, discard a card.

Hexproof
When Wary Watchkeeper enters the battlefield, target player mills three cards.

Haste
When Wasteland Rabblerousers enters the battlefield, creatures your opponents control with power X or less can't block this turn, where X is the number of Deserts you control.

Trample
When Wasteland Ravagers enters the battlefield, you may sacrifice a land or exile a land card from your graveyard. If you do, creatures you control get +1/+0 and gain haste until end of turn.

When Wavebreaker enters the battlefield, add two mana of any one color. You can't spend this mana to cast spells.

When Wayfaring Realmstitcher enters the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

When Wayfaring Swindler enters the battlefield, destroy all permanents attached to target creature.

When Wayward Bloodseeker enters the battlefield, put a +1/+1 counter on up to one target creature you control. When you do, Wayward Bloodseeker deals damage to any target equal to the number of permanents you control with counters on them.

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

When Weald Wanderer enters the battlefield, you gain 3 life and each opponent loses 2 life.
{1}, Pay 1 life: Shuffle Weald Wanderer into its owner's library. If you do, draw a card.

When Wealthy Merchants enters the battlefield, create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

When Weary Adventurer enters the battlefield, return a permanent you control to its owner's hand.