Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters, you may pay 2 life. If you don't, it enters tapped.

Curiosity

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Spectral Sailor

Flash (You may cast this spell any time you could cast an instant.)
Flying
{3}{U}: Draw a card.

Jubilant Skybonder

Flying
Creatures you control with flying have "Spells your opponents cast that target this creature cost {2} more to cast."

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Glacial Fortress

Glacial Fortress enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Port Town

As Port Town enters, you may reveal a Plains or Island card from your hand. If you don't, Port Town enters tapped.
{T}: Add {W} or {U}.

Skycat Sovereign

Flying
Skycat Sovereign gets +1/+1 for each other creature you control with flying.
{2}{W}{U}: Create a 1/1 white Cat Bird creature token with flying.

Empyrean Eagle

Flying
Other creatures you control with flying get +1/+1.

Island

Watcher of the Spheres

Flying
Creature spells with flying you cast cost {1} less to cast.
Whenever another creature you control with flying enters, Watcher of the Spheres gets +1/+1 until end of turn.

Outflank

Outflank deals damage to target attacking or blocking creature equal to the number of creatures you control.

Pteramander

Flying
{7}{U}: Adapt 4. This ability costs {1} less to activate for each instant and sorcery card in your graveyard. (If this creature has no +1/+1 counters on it, put four +1/+1 counters on it.)

Mana Leak

Counter target spell unless its controller pays {3}.

Rally of Wings

Untap all creatures you control. Creatures you control with flying get +2/+2 until end of turn.

Unsubstantiate

Return target spell or creature to its owner's hand.

Staggering Insight

Enchant creature
Enchanted creature gets +1/+1 and has lifelink and "Whenever this creature deals combat damage to a player, draw a card."

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Plains

Warden of Evos Isle

Flying
Creature spells with flying you cast cost {1} less to cast.

Loyal Pegasus

Flying
Loyal Pegasus can't attack or block alone.

Gift of the Fae

Target creature gets +2/+1 and gains flying until end of turn. (Then exile this card. You may cast the creature later from exile.)