msem-instigator

As an additional cost to cast this spell, sacrifice a creature.
Look at the top three cards of your library. Put two of them into your hand and the other into your graveyard.

Germinate three times. You lose 3 life. (To germinate, put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)

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.)

{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.

Each opponent sacrifices a creature. For each creature sacrificed this way, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

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.

Menace
Whenever Wightclaw deals combat damage to a player, that player discards a card and you 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 this creature dies, each opponent draws a card” as long as it has a bounty counter on it.)

When Wild Hermit dies, create a 2/2 white Cat creature token.
Revive—{3}{G}{G}, Sacrifice a creature. ({3}{G}{G}, Sacrifice a creature, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Whenever you cast a creature spell, if it has a creature type no creature you control has, upgrade Wild Outlander. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Vigilance
• Trample

Wild Pyromancy deals 2 damage to each creature, player, and planeswalker. If you cast this spell during your main phase, Wild Pyromancy deals 3 damage to each creature, player, and planeswalker instead.

Colossal 4—{5}{G} (You may cast this for its colossal cost to have it enter with four +1/+1 counters; or pay {5}{G} as a sorcery: Put four +1/+1 counters on it if it has none.)
Trample

Whenever a creature blocks Wildborn Courtesan, draw a card.
{R}{R}: Untap target creature an opponent controls. That creature blocks Wildborn Courtesan this turn if able.

At the beginning of combat on your turn, if you control a creature with power 4 or greater, put a +1/+1 counter on Wilderkin Zealot.
{R}{G}: Target creature gains trample until end of turn.

{2}{R/G}: Wildershrine Warden gets +2/+2 until end of turn. You may have it assign its combat damage this turn as though it weren't blocked. Activate only once each turn.

Harmony — You may pay {1}{G}. If you do, create a 3/3 green Beast creature token.
When Wildheart Chorister enters, harmonize. (Trigger up to one harmony of a permanent you control.)

{T}: Add {C}.
{5}, {T}, Sacrifice Wildkin Grove: Create three 1/1 colorless Shapeshifter creature tokens with changeling. (They're every creature type.)

Flying
{U}, Sacrifice Willow Spirit: Counter target spell or ability that targets you or a creature you control.

Destroy target artifact or enchantment.
Cycling {2} ({2}, Discard this card: Draw a card.)

{1}{G}, Remove a -1/-1 counter from a creature you control: Wiltthorn Elemental gets +2/+2 until end of turn.

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.

All creatures get -1/-1 until end of turn.
If ten or more cards are in your graveyard, creatures your opponents control get an additional -1/-1 until end of turn.

Windworn Spires enters tapped.
{T}: Add {R}.
Desertcycling {1}{R} ({1}{R}, Discard this card: Search your library for a Desert card, reveal it, and put it into your hand, then shuffle.)

Whenever equipped creature deals combat damage to a player, create a 1/1 colorless Thopter artifact creature token with flying.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Flying
{T}, Exile two cards from your graveyard: Add one mana of any color.