Enduring Curiosity

Flash
Whenever a creature you control deals combat damage to a player, draw a card.
When Enduring Curiosity dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)

Dazzling Denial

Counter target spell unless its controller pays {2}. If you control a Bird, counter that spell unless its controller pays {4} instead.

Appa, Steadfast Guardian

Flash
Flying
When Appa enters, airbend any number of other target nonland permanents you control. (Exile them. While each one is exiled, its owner may cast it for {2} rather than its mana cost.)
Whenever you cast a spell from exile, create a 1/1 white Ally creature token.

Shiko, Paragon of the Way

Flying, vigilance
When Shiko enters, exile target nonland card with mana value 3 or less from your graveyard. Copy it, then you may cast the copy without paying its mana cost. (A copy of a permanent spell becomes a token.)

Aang and La, Ocean's Fury

Reach, trample
Whenever Aang and La attack, put a +1/+1 counter on each tapped creature you control.

Aang, Swift Savior

Flash
Flying
When Aang enters, airbend up to one other target creature or spell. (Exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)
Waterbend {8}: Transform Aang.

Aang, Swift Savior // Aang and La, Ocean's Fury

Aven Interrupter

Flash
Flying
When this creature enters, exile target spell. It becomes plotted. (Its owner may cast it as a sorcery on a later turn without paying its mana cost.)
Spells your opponents cast from graveyards or from exile cost {2} more to cast.

Extraordinary Journey

When this enchantment enters, exile up to X target creatures. For each of those cards, its owner may play it for as long as it remains exiled.
Whenever one or more nontoken creatures enter, if one or more of them entered from exile or was cast from exile, you draw a card. This ability triggers only once each turn.

Lightstall Inquisitor

Vigilance
When this creature enters, each opponent exiles a card from their hand and may play that card for as long as it remains exiled. Each spell cast this way costs {1} more to cast. Each land played this way enters tapped.

All Aboard

Exile target non-Pilot creature you control, then return that card to the battlefield under its owner's control.

Skycoach Conductor

Flash
Flying, vigilance
This creature enters prepared. (While it's prepared, you may cast a copy of its spell. Doing so unprepares it.)

Skycoach Conductor // All Aboard

Floodpits Drowner

Flash
Vigilance
When this creature enters, tap target creature an opponent controls and put a stun counter on it.
{1}{U}, {T}: Shuffle this creature and target creature with a stun counter on it into their owners' libraries.

Voracious Tome-Skimmer

Flying
Whenever you cast a spell during an opponent's turn, you may pay 1 life. If you do, draw a card.

Brineborn Cutthroat

Flash (You may cast this spell any time you could cast an instant.)
Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on this creature.

Flitterwing Nuisance

Flying
This creature enters with a -1/-1 counter on it.
{2}{U}, Remove a counter from this creature: Whenever a creature you control deals combat damage to a player or planeswalker this turn, draw a card.