When Adaptive Hydra enters, teach it your choice of haste, menace, or vigilance. Then repeat this process X times.

Aethersteel Pouncer enters with a haste counter on it.

Haste
When Assault Engine enters, gain control of target creature and untap it. Sacrifice it at the beginning of the next end step.
Crew 2

{U}{R}{W}: Creatures you control get +1/+1 until end of turn.

Bioengineered Opus enters with three +1/+1 counters, a lifelink counter, and a vigilance counter on it.
When Bioengineered Opus dies, for each creature you control, you may move a counter from Bioengineered Opus onto that creature.

Creatures you control have “{T}: Create a Treasure token.”
{W}{U}{B}{R}{G}, Sacrifice Black-Tie Gala: Draw two cards.

Return target nonland permanent to its owner's hand. Then that player reveals their hand. You choose a nonland card from it. That player discards that card.

Flying
When Blooming Sauropod enters, create two Berry tokens, then sacrifice any number of Berries. For each Berry sacrificed this way, put a +1/+1 counter on another creature you control.

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. If this spell's flashback cost was paid, instead search your library for any number of land cards, put them onto the battlefield tapped, then shuffle.
Flashback {3}{W}{U}{B}{R}{G}

Draw two cards. If {W} was spent to cast this spell, you gain 2 life. If {B} was spent to cast this spell, each opponent loses 2 life.

Vigilance
Once each turn, if you would put one or more counters on a creature you control, you may put that many of each of those kinds of counters on each creature you control instead.

{W}, Exile an artifact or enchantment card from your graveyard: You gain 3 life.
{2}{U}, Exile an instant or sorcery card from your graveyard: Draw a card.
{4}{B}, Exile a creature or planeswalker card from your graveyard: Create a tapped 0/0 colorless Robot artifact creature token with three +1/+1 counters on it.

{W}: Charismatic Chameleon gains lifelink until end of turn.
{1}{R}: Charismatic Chameleon gets +1/+1 until end of turn.
{2}{U}: Charismatic Chameleon can't be blocked this turn.

Flying
Whenever Chief Executive Dhante enters or attacks, create a Treasure token, then you may pay {X}. Spend only mana from artifact sources, and X can't be 0. When you do, destroy target nonland permanent with mana value X or less.

When Codename: Spyder enters, mill three cards.
Whenever one or more cards are put into your graveyard from your library, you may return up to one of those cards to your hand. Do this only once each turn.

Choose up to X target creatures. Switch their power and toughness until end of turn.
All creatures get -3/-3 until end of turn.

Ward {3}
Daunting Snapper can't be blocked by creatures with power 2 or less.

Ward {2}
Amity — Whenever you attack with Dazzling Performer and exactly one other creature, put a +1/+1 counter on each of those creatures. Until end of turn, they gain trample and “Whenever this creature deals combat damage to a player, draw a card.”

Add {W}{U}{B}{R}.

Exile target creature. Distribute two +1/+1 counters among up to two target creatures you control.

Vigilance
Once each turn, when you activate a nonmana ability, you may copy it. You may choose new targets for the copy.
{1}{U}{R}{W}, {T}: Tap target creature. Echocrafter deals 1 damage to that creature's controller.

Create a Solidarity token. When you do, pay for and choose any number.
+{R} — Edgeland Pledge deals 2 damage to any target.
+{U} — Tap up to three target creatures.
+{G} — Create a 1/1 red Soldier creature token. It gains haste until end of turn.

Amity — Whenever you attack with Elegant Hunter and exactly one other creature, choose one —
• Attacking creatures you control get +2/+0 until end of turn.
• Attacking creatures you control can't be blocked this turn.

Legendary permanents you control have “{1}, {T}: Tap target creature.”
At the beginning of each end step, scry 1 if you spent {U} to activate abilities this turn, Ema deals 1 damage to each opponent if you spent {R}, and put a +1/+1 counter on a creature you control if you spent {W}.

Trample
Other creatures have base power and toughness 3/3.
At the beginning of your end step, sacrifice Eo unless you attacked this turn.