msem-instigator

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.

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.

Changeling (This card is every creature type.)
Watcher of the Polyps has all names of creature cards in addition to its name as long as it's on the battlefield.
Watcher of the Polyps gets +X/+X, where X is the greatest number of creatures you control with the same name.

Flying

If you would gain life this turn, you gain twice that much life instead.
Draw a card.

Equipped creature gets +2/+2 and has vigilance.
Equip {4}
Wanderlust — Wayfarer's Adornments has equip {0} as long as you control four or more differently named lands.

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.”)

Whenever Whisperer of Fortunes attacks, the next card you foretell this turn costs {0} to foretell.
Whenever you cast a foretold spell, put a +1/+1 counter on Whisperer of Fortunes. It gains flying until end of turn.

Haste
Ride {R} ({R}: Transform this and attach it to target creature you control without a Mount. Ride only as a sorcery.)

Assault {2}{G} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Wildborn Marauder assaults, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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

Windworn Spires enters the battlefield 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.)

Wise Old Oak enters the battlefield tapped unless you control a basic Forest.
{T}: Add {G}.
{3}{G}{G}: Until end of turn, Wise Old Oak becomes a 4/4 green Treefolk creature with “Whenever this creature deals combat damage to a player, draw a card.” It's still a land.

Deathtouch
At the beginning of your end step, create a 1/1 black Rat creature token with “This creature can't block.”
{1}{B}, {T}, Sacrifice three other creatures: Each opponent discards a card and loses 2 life. You draw a card and gain 2 life.

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.

Witchseeker Mob's power and toughness are each equal to twice the number of Citizens and/or Peasants you control.
When Witchseeker Mob enters the battlefield, exile target nonland permanent an opponent controls with mana value less than or equal to Witchseeker Mob's power until Witchseeker Mob leaves the battlefield.

{T}: Tap target creature. Activate only if Wizened Veteran is embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

{T}: Add {C}.
{3}, {T}: Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Trample
World Tender's power and toughness are each equal to twice the number of differently named lands you control.

{2}{W}, Exile Worldwise Ascetic from your graveyard: Create a green Aura enchantment token named Years of Experience attached to target creature. The token has enchant creature and “Enchanted creature gets +2/+2.” Activate only as a sorcery.

Flying
Assault {2}{B} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Wretched Lammasu assaults, each opponent discards a card.

(As this Discovery enters and after your draw step, add a progress counter. Stop after you've discovered.)
I, II — Draw a card.
Discovery — Noncreature spells you cast cost {1} less to cast.

Foretell {1}{U}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
Counter target spell. If this spell was foretold, draw a card.

Menace
Yaran's Enforcer gets +1/+1 as long as you foretold a card this turn.
Yaran's Enforcer gets +1/+1 as long as you cast a foretold spell this turn.

Foretell {2}{U}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
Choose one. If this spell was foretold, you may choose both instead —
• Draw three cards, then discard two cards.
• The owner of target nonland permanent puts it on the top or bottom of their library.