msem-instigator

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 Brine Kelpie attacks, you may tap target creature an opponent controls.
Ride {2}{U} ({2}{U}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

Improve {1}{W} ({1}{W}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Prevent all combat damage that would be dealt to attacking embattled creatures you control. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Choose one —
• Dispersive Volley deals 1 damage to each of up to three target attacking or blocking creatures.
• Target player sacrifices an enchantment.

Dominance — When Mammoth Crab enters, draw a card if you control the creature with the greatest power or tied for the greatest power.

Flash
Flying
If an effect an opponent controls would cause them to take an extra turn, you take an extra turn instead.
{G}{U}: Return another creature you control to its owner's hand. Activate this ability only once each turn.

Flash
When Guppyfin Duelist enters, create a green Aura enchantment token named Piranha's Prowess attached to target creature. The token has enchant creature and “Enchanted creature gets +2/+2.” Untap that creature.

{T}: Add {C}.
{T}, Tap an untapped artifact, creature, or land you control: Add one mana of any color.
{T}: Choose a card name, then reveal the top card of your library. If that card has the chosen name, you may sacrifice Sealed Archives and draw a card.

When Horizon Gazer enters, reveal the top two cards of your library. Put a noncreature card revealed this way into your hand and the rest into your graveyard.
Ascend {3}{G} ({3}{G}: Exile this creature, then return it to the battlefield transformed. Ascend only as a sorcery.)

{T}, Discard a card: Draw a card from each of your libraries.
{1}{U}{R}, {T}, Discard your hand: Return each Study card from your graveyard to your hand.

When Fables of the Bold enters, draw a card.
Enchanted creatures you control get +1/+1.

Target creature gets -3/-3 until end of turn. If you control a legendary creature, instead destroy that creature.

When Miasma Spewer enters, you may sacrifice a permanent. When you do, Miasma Spewer deals 1 damage to each opponent and each creature and planeswalker they control.

Deathtouch
When this creature enters, if you cast it, target creature card in your graveyard gains arise until end of turn. Its arise cost is equal to its mana cost. (Exile that card from your graveyard and pay its arise cost as a sorcery: Create a black token copy of it that's also a Zombie and can't block.)

Palace of Tomorrows enters tapped.
{T}: Add {U}.
{2}{U}, {T}: Target player mills three cards.

(As an Encounter enters, choose an opponent to protect it. You and others can attack it. When defense counters are removed, create a 0/0 Army token if you don't control one, then put that many +1/+1 counters on a Army you control.)
Whenever a creature you control attacks Figments of the Muktann, create a token that's a copy of that creature that's tapped and attacking the player protecting Figments of the Muktann. Sacrifice the token at the beginning of the next end step.

Germinate, then creatures you control that are Saprolings or have counters on them gain indestructible until end of turn. (To germinate, put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)

Flash
Flying
At the beginning of each end step, if two or more spells were cast this turn, you may draw a card. If you do, discard a card.

Weathered Fortress enters tapped.
{T}: Add {U} or {R}.
{U}{R}: Until end of turn, Weathered Fortress becomes a 1/4 blue and red Golem creature with with “When this creature attacks, switch its power and toughness until end of turn” and “Whenever this creature attacks or blocks, torment yourself.” It's still a land. (To torment yourself, lose 3 life unless you discard a card or sacrifice a nonland permanent.)

Enchant creature
When Til Death enters, exile target creature an opponent controls other than enchanted creature until Til Death leaves the battlefield.
Enchanted creature has defender.

Exile target artifact, enchantment, or creature with flying.

Resolute — At the beginning of combat on your turn, if Glisterhorn's power is greater than its base power, tap target creature an opponent controls.

Doomsday Horde enters tapped unless it was foreshadowed.
When Doomsday Horde dies, search your library for a card, put it into your hand, then shuffle.
Foreshadow {3}{B}{B}{B} (You may cast this spell for its foreshadow cost. If you do, also trigger its “dies” abilities when it enters.)

Exile target creature. Its controller loses 3 life.