msem-instigator

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

Tap target creature. If you control a Monk, draw a card. (Then exile this card. You may cast the creature later from exile.)

Flying

{3}, Sacrifice Titanic Fossil: Mill three cards, then you may exile a card from your graveyard. You may cast a copy of the exiled card without paying its mana cost if the spell's mana value is 3 or less. Activate only as a sorcery.
{3}{U}{B}: Return Titanic Fossil from your graveyard to the battlefield transformed. Activate only during your turn.

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

Chosen one ({W}{U}{B}{R}{G}: Transform this permanent.)
When Tomb Steward enters, search your library for a card and put it into your graveyard. Then shuffle.

Ward {2}
Even numbered spells you cast each turn costs {2} less to cast. (The second, fourth, sixth, etc.)

Vigilance, reach
When this creature transforms into Towering Alpha, return target card from your graveyard to your hand.
At the beginning of your end step, if Towering Alpha didn't attack this turn, transform it.

Whenever Toxic Miscreant deals combat damage to a player, that player discards a card.

Search your library for a creature card, reveal it, then shuffle and put that card second from the top.

Draw a card. (Cast a copy of this spell once while this creature is on the battlefield.)

Vigilance, reach
When Treeline Archer enters, mill four cards.
{5}{G}: Transform Treeline Archer. Activate only if it's attacking.

Deathtouch

Menace
{3}{R}: Transform Troublesome Throng. Activate only if it's attacking.

(Transform this if it's not attached to a creature. Pay {2}{W} as a sorcery to unattach it.)
Enchant creature you control
Trusty Steed's rider gets +2/+2.

Hexproof
Whenever this creature transforms into Tsunami Titan or attacks, you may return target creature to its owner's hand.

Double strike
Ride {2}{W} ({2}{W}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

Target player loses 3 life and you gain 3 life. (Then exile this card. You may cast the creature later from exile.)

Menace
Chosen one ({W}{U}{B}{R}{G}: Transform this permanent.)

Sacrifice a creature: Two-Faced Aristocrat gains indestructible until end of turn.
Attain {4}{B} ({4}{B}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Trample, haste
When Tyrants of Bundan enters, tap all lands target player controls. They don't untap during their controller's next untap step.

You may look at the top card of your library any time.
You may cast creature spells from the top of your library.
At the beginning of your end step, if Ulvenwald Howler didn't attack this turn, transform it.

When Ulvenwald Ranger enters, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
{1}{G}: Transform Ulvenwald Ranger. Activate only if it's attacking.

Target creature gets -5/-0 until end of turn. (Then exile this card. You may cast the creature later from exile.)

Unbound Spirit can't be blocked.
When you attain Unbound Spirit, tap target creature. That creature doesn't untap during its controller's next untap step.