msem-instigator

Double your life total. (Then exile this card. You may cast the creature later from exile.)

Prowess
Unveil {2}{U}{R} ({2}{U}{R}: Transform this. Unveil only as a sorcery.)

Prowess, trample
Whenever Brilliant Diviner deals combat damage to a player, draw a card.

{2}{R}: Target creature can't block Brimstone Courser this turn.
Ride {3}{R}{R} ({3}{R}{R}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

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.)

Create two 1/1 green Insect creature tokens. (Cast a copy of this spell once while this creature is on the battlefield.)

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
When Budding Companion has three or more +1/+1 counters on it, remove them all and transform it.

First strike
Ascend {1}{B} ({1}{B}: Exile this creature, then return it to the battlefield transformed. Ascend only as a sorcery.)

Exile the top card of your library. You may play that card until the end of your next turn.

Whenever Burning Hart deals combat damage to a player, it deals that much damage to up to one target planeswalker that player controls.

Search your library for a card, put it into your graveyard, then shuffle. (Then exile this card. You may cast the creature later from exile.)

Butcher deals 3 damage to target player. (Cast a copy of this spell once while this creature is on the battlefield.)

This spell can't be countered.
Search your library for a basic land or a Hydra card not named Aurora Hydra, reveal it, and put it into your hand. Then shuffle.

Search your library for a Dragon card, reveal it, put it into your hand, then shuffle. It deals damage equal to its power to you.

Ascend—{W}{B}, Discard a card, Sacrifice a creature, Exile a creature card from your graveyard. ({W}{B}, Discard a card, Sacrifice a creature, Exile a creature card from your graveyard: Exile this creature, then return it to the battlefield transformed. Ascend only as a sorcery.)

Vigilance
Unveil {2}{G}{W} ({2}{G}{W}: Transform this. Unveil only as a sorcery.)

Return target tapped creature to its owner's hand. (Then exile this card. You may cast the creature later from exile.)

Whenever Cattish Bluestocking deals combat damage to a player, draw a card.
Attain {4}{U} ({4}{U}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

When Cave Eel enters the battlefield, look at the top three cards of your library. Put one on top and the rest on the bottom in any order.

First strike
Whenever a creature blocks Celestial Conscript, put a -1/-1 counter on that creature.

Legacy (You may play this side of this card only from your graveyard. Exile it if it would be put into a graveyard or not resolve.)
Shuffle any number of target cards in graveyards into their owners' libraries.
Scry 2, then you gain 3 life.

Trample
Whenever Charging Cassowary deals combat damage to a player, you may cast a copy of an Adventure of a permanent you control.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
When Cheerful Generator has three or more +1/+1 counters on it, remove them all and transform it.

{1}, Sacrifice a creature: Put a +1/+1 counter on Chitterrax, then each opponent loses 1 life and you gain 1 life.

Haste
Claret Gorger can't block.
Unveil {2}{B}{R} ({2}{B}{R}: Transform this. Unveil only as a sorcery.)