Island

Archaeomancer

When Archaeomancer enters the battlefield, return target instant or sorcery card from your graveyard to your hand.

Tome Raider

Flying
When Tome Raider enters the battlefield, draw a card.

Augury Owl

Flying
When Augury Owl enters the battlefield, scry 3. (Look at the top three cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Preening Champion

Flying
When Preening Champion enters the battlefield, create a 1/1 blue and red Elemental creature token.

Thriving Isle

Thriving Isle enters the battlefield tapped.
As Thriving Isle enters the battlefield, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Protocol Knight

When Protocol Knight enters the battlefield, tap target creature an opponent controls. Put a stun counter on that creature if you control another Knight. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Counterspell

Thassa, Deep-Dwelling

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature.
At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control.
{3}{U}: Tap another target creature.

Brinebarrow Intruder

Flash
When Brinebarrow Intruder enters the battlefield, target creature an opponent controls gets -2/-0 until end of turn.

Cryptic Spires

As you create your deck, circle two of the colors below.
Cryptic Spires enters the battlefield tapped.
{T}: Add one mana of either of the circled colors.

Conjurer's Closet

At the beginning of your end step, you may exile target creature you control, then return that card to the battlefield under your control.

Sage's Row Denizen

Whenever another blue creature enters the battlefield under your control, target player mills two cards.

Aether Channeler

When Aether Channeler enters the battlefield, choose one —
• Create a 1/1 white Bird creature token with flying.
• Return another target nonland permanent to its owner's hand.
• Draw a card.

Illusionist's Stratagem

Exile up to two target creatures you control, then return those cards to the battlefield under their owner's control.
Draw a card.