Merfolk Spy

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Whenever Merfolk Spy deals combat damage to a player, that player reveals a card at random from their hand.

Faerie Miscreant

Flying
When Faerie Miscreant enters, if you control another creature named Faerie Miscreant, draw a card.

Mist-Cloaked Herald

Grazilaxx, Illithid Scholar

Whenever a creature you control becomes blocked, you may return it to its owner's hand.
Whenever one or more creatures you control deal combat damage to a player, draw a card.

Mausoleum Wanderer

Flying
Whenever another Spirit you control enters, Mausoleum Wanderer gets +1/+1 until end of turn.
Sacrifice Mausoleum Wanderer: Counter target instant or sorcery spell unless its controller pays {X}, where X is Mausoleum Wanderer's power.

Cloud Pirates

Flying
Cloud Pirates can block only creatures with flying.

Artificer's Assistant

Flying
Whenever you cast a historic spell, scry 1. (Artifacts, legendaries, and Sagas are historic. To scry 1, look at the top card of your library, then you may put that card on the bottom.)

Siren Stormtamer

Flying
{U}, Sacrifice Siren Stormtamer: Counter target spell or ability that targets you or a creature you control.

Triton Shorestalker

Galerider Sliver

Sliver creatures you control have flying.

Hope of Ghirapur

Flying
Sacrifice Hope of Ghirapur: Until your next turn, target player who was dealt combat damage by Hope of Ghirapur this turn can't cast noncreature spells.

Wingcrafter

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Wingcrafter is paired with another creature, both creatures have flying.

Jace's Phantasm

Flying
Jace's Phantasm gets +4/+4 as long as an opponent has ten or more cards in their graveyard.

Gudul Lurker

Gudul Lurker can't be blocked.
Megamorph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

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.

Flying Men

Grayscaled Gharial

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

Temporal Manipulation

Temporal Mastery

Take an extra turn after this one. Exile Temporal Mastery.
Miracle {1}{U} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Rishadan Dockhand

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
{1}, {T}: Tap target land.

Silver Raven

Flying
When Silver Raven enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Zephyr Sprite

Slither Blade

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Time Warp

Target player takes an extra turn after this one.

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.

Castle Vantress

Castle Vantress enters tapped unless you control an Island.
{T}: Add {U}.
{2}{U}{U}, {T}: Scry 2.

Cloud Sprite

Flying (This creature can't be blocked except by creatures with flying or reach.)
Cloud Sprite can block only creatures with flying.

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Jeweled Lotus

{T}, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

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.)

Time Stretch

Target player takes two extra turns after this one.

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Faerie Seer

Flying
When Faerie Seer enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Merfolk Windrobber

Flying
Whenever Merfolk Windrobber deals combat damage to a player, that player mills a card. (They put the top card of their library into their graveyard.)
Sacrifice Merfolk Windrobber: Draw a card. Activate only if an opponent has eight or more cards in their graveyard.

Spectral Sailor

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