{U}: Exile Aetherling. Return it to the battlefield under its owner's control at the beginning of the next end step.

{U}: Aetherling can't be blocked this turn.

{1}: Aetherling gets +1/-1 until end of turn.

{1}: Aetherling gets -1/+1 until end of turn.

{U}: Exile Aetherling. Return it to the battlefield under its owner's control at the beginning of the next end step.

{U}: Aetherling can't be blocked this turn.

{1}: Aetherling gets +1/-1 until end of turn.

{1}: Aetherling gets -1/+1 until end of turn.

Flying

When Angel of Serenity enters the battlefield, you may exile up to three other target creatures from the battlefield and/or creature cards from graveyards.

When Angel of Serenity leaves the battlefield, return the exiled cards to their owners' hands.

When Augur of Bolas enters the battlefield, look at the top three cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

When Augur of Bolas enters the battlefield, look at the top three cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

When Augur of Bolas enters the battlefield, look at the top three cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Azorius Guildgate enters the battlefield tapped.

{T}: Add {W} or {U}.

Azorius Guildgate enters the battlefield tapped.

{T}: Add {W} or {U}.

Azorius Guildgate enters the battlefield tapped.

{T}: Add {W} or {U}.

Azorius Guildgate enters the battlefield tapped.

{T}: Add {W} or {U}.

When Detention Sphere enters the battlefield, you may exile target nonland permanent not named Detention Sphere and all other permanents with the same name as that permanent.

When Detention Sphere leaves the battlefield, return the exiled cards to the battlefield under their owner's control.

When Detention Sphere enters the battlefield, you may exile target nonland permanent not named Detention Sphere and all other permanents with the same name as that permanent.

When Detention Sphere leaves the battlefield, return the exiled cards to the battlefield under their owner's control.

When Detention Sphere enters the battlefield, you may exile target nonland permanent not named Detention Sphere and all other permanents with the same name as that permanent.

When Detention Sphere leaves the battlefield, return the exiled cards to the battlefield under their owner's control.

Counter target creature spell.

Counter target creature spell.

Counter target creature spell.

Counter target creature spell.

({T}: Add {W} or {U}.)

As Hallowed Fountain enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

({T}: Add {W} or {U}.)

As Hallowed Fountain enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

({T}: Add {W} or {U}.)

As Hallowed Fountain enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

({T}: Add {W} or {U}.)

As Hallowed Fountain enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

+1: Until your next turn, whenever a creature an opponent controls attacks, it gets -1/-0 until end of turn.

-2: Reveal the top three cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other on the bottom of your library in any order.

-8: For each player, search that player's library for a nonland card and exile it, then that player shuffles. You may cast those cards without paying their mana costs.

+1: Until your next turn, whenever a creature an opponent controls attacks, it gets -1/-0 until end of turn.

-2: Reveal the top three cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other on the bottom of your library in any order.

-8: For each player, search that player's library for a nonland card and exile it, then that player shuffles. You may cast those cards without paying their mana costs.

+1: Until your next turn, whenever a creature an opponent controls attacks, it gets -1/-0 until end of turn.

-2: Reveal the top three cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other on the bottom of your library in any order.

-8: For each player, search that player's library for a nonland card and exile it, then that player shuffles. You may cast those cards without paying their mana costs.

+1: Until your next turn, whenever a creature an opponent controls attacks, it gets -1/-0 until end of turn.

-2: Reveal the top three cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other on the bottom of your library in any order.

-8: For each player, search that player's library for a nonland card and exile it, then that player shuffles. You may cast those cards without paying their mana costs.

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

({T}: Add {W}.)

You gain X life and draw X cards.

You gain X life and draw X cards.

You gain X life and draw X cards.

This spell can't be countered.

Destroy all creatures.

This spell can't be countered.

Destroy all creatures.

This spell can't be countered.

Destroy all creatures.

This spell can't be countered.

Destroy all creatures.

Counter target spell unless its controller pays {X}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Counter target spell unless its controller pays {X}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Counter target spell unless its controller pays {X}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Indestructible

As long as your devotion to blue is less than five, Thassa isn't a creature. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

At the beginning of your upkeep, scry 1.

{1}{U}: Target creature you control can't be blocked this turn.