msem-instigator

Whenever Wadepool Frog attacks, it gains flying until end of turn.

Flying
Wailing Soul has hexproof as long as it's not attacking or blocking.

Whenever Wakeborne Kraken or another Kraken, Leviathan, Octopus, or Serpent you control enters, you may return target creature an opponent controls to its owner's hand.
Whenever a creature an opponent controls leaves the battlefield, if it didn't die, draw a card.

Whenever Waketide Serpent attacks, you may pay {2}{U}. If you do, tap target creature. It doesn't untap during its controller's next untap step.

Glitch {1} (Remove one [restriction] for each time you pay the glitch cost.)
Target creature gains hexproof [from abilities] until end of turn and can't be blocked [by creatures with greater power than it] this turn.

Enchant creature
Enchanted creature can't block or be blocked.
{U}: Enchanted creature gets +1/+0 or -1/-0 until end of turn.

Defender (This creature can't attack.)
Mirage {0} (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.)

Defender
Whenever one or more creatures you control deal combat damage to a player, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
When Wall of Notes dies, draw a card.

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

Return target creature to its owner's hand. That player can't cast spells with the same name as that creature during their next turn.

When a creature you control scavenges Wanderer of Many, create a token that's a copy of that creature. Put a +1/+1 counter on the copy.
Scavenge {3}{U} ({3}{U}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Wanderer's Sky enters tapped.
As Wanderer's Sky enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Flying
Whenever Wandering Dragonfly or another creature you control enters, you may draw a card. If you do, discard a card.

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

Defender
When Warden of Silence enters, draw a card.

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

You may have Warped Physiognomist enter as a copy of any creature on the battlefield with mana value 3 or less.

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)

When Warping Relic enters or is put into a graveyard from the battlefield, choose one —
• Draw two cards, then discard a card.
• Return another target nonland permanent to its owner's hand.
• Choose any number of target creatures. Switch their power and toughness until end of turn.

Invigorate 1, then untap each creature you control with a +1/+1 counter on it. (Choose a creature with the least power among creatures you control and put a +1/+1 counter on it.)

When Warrior's Perspective enters, 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.

Enchant creature
Enchanted creature is a blue Frog with base power and toughness 1/1 and loses all other card types, creature types and abilities.

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