msem-instigator

Whenever you draw a card, target player mills two cards.
Whenever you cast a blue spell, scry 1, then you may reveal the top card of your library. If it's an instant or sorcery card, draw a card.

Enchant creature
Enchanted creature can't attack or block.
{2}{U}: Return Whiplash and enchanted creature to their owners' hands.

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

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

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 it dies, each opponent draws a card” as long as it has a bounty counter on it.)

When Wild Festivities enters the battlefield 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.

(Choose only one work as a sorcery to add its ability.)
When Wildlife Sketches enters the battlefield, reveal the top five cards of your library. Put a creature card from among them into your hand and the rest on the bottom in any order.
{1}{G}: Carnation Petals
You may cast creature spells as though they had flash.
{3}{G}: Pecking Order
At the beginning of your upkeep, you may sacrifice a creature. If you do, search your library for a creature card with mana value equal to 1 plus the sacrificed creature's mana value, put it onto the battlefield, then shuffle.

At the beginning of each player's upkeep, you may exile target permanent that player controls. If you do, return that card to the battlefield under its owner's control at the beginning of the next end step.

Enchant creature
You may cast this spell from your graveyard if it targets a legendary creature you control.
Enchanted creature gets +2/+2 and has flying.

Enchant creature with flying
Enchanted creature can't attack or block, and it loses all abilities other than flying.

Flash
Enchant creature
Enchanted creature gets +2/+2 and has flying and “At the beginning of your upkeep, you lose 1 life and create a 1/1 black Harpy creature token with flying.”

[+1]: Until end of turn, Winmeari, Glorian Defector becomes a 5/5 Warrior creature with lifelink that's still a planeswalker. Prevent all damage that would be dealt to her this turn.
[0]: Create a 2/2 black Zombie creature token.
[–1]: You get an emblem with “Attacking creatures your opponents control must attack a Winmeari planeswalker if able.”

Archive 3 (As this enters the battlefield, shuffle the top three cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
You may cast the top card of the archived library. Whenever you do, copy that spell. You may choose new targets for the copy.

[+1]: Add {R} or {G}. You can't spend this mana to cast an Elf spell.
[–2]: Winona, the Heretic deals 4 damage to any target. If that target is an Elf, Winona deals 4 damage to that Elf's controller.
[–6]: Until end of turn, any time you could cast an instant, you may pay {R}. When you do, Winona deals 2 damage to any target.

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 a creature is returned to your hand, scry 1.
{4}{G}{U}: Reveal the top card of your library. If it's a permanent card, you may put it onto the battlefield.

When Wise Farseer Chini enters the battlefield, create a tapped colorless land token named Far-Off Lands with “{T}: Add one mana of any color.”

Enspirit (As you cast this spell, you may exile a nonenchantment creature you control until this leaves the battlefield or fails to resolve. Reduce this spell's cost by the exiled card's mana value.)
You may have Witch of Shifting Waters enter the battlefield as a copy of any creature on the battlefield, except it's an enchantment in addition to its other types.

Flash
When Witch's Invocation enters the battlefield, draw a card.
You may cast spells as though they had flash.

Prowess
Curse spells you cast cost {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay.
Whenever you cast a Curse spell, you may draw a card.

Whenever Witchfinder Artur enters the battlefield 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.

Whenever you cast a noncreature spell, you may pay {1}. If you do, scry 2. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

If you would draw a card, you may draw two cards and have each opponent draw a card instead.
Spells cost {1} less to cast if a player cast a spell this turn.

At the beginning of your upkeep, if there are three or more colors among permanents you control, you gain 2 life and draw a card.

Whenever a nontoken creature enters the battlefield under your control, you may scry 1. (To scry 1, look at the top card of your library. You may put that card on the bottom of your library.)