Reef Shaman

{T}: Target land becomes the basic land type of your choice until end of turn.

Halimar Depths

Halimar Depths enters tapped.
When Halimar Depths enters, look at the top three cards of your library, then put them back in any order.
{T}: Add {U}.

Ink Dissolver

Kinship — At the beginning of your upkeep, you may look at the top card of your library. If it shares a creature type with Ink Dissolver, you may reveal it. If you do, each opponent mills three cards.

Aether Adept

When Aether Adept enters, return target creature to its owner's hand.

Lonely Sandbar

Lonely Sandbar enters tapped.
{T}: Add {U}.
Cycling {U} ({U}, Discard this card: Draw a card.)

Martyr of Frost

{2}, Reveal X blue cards from your hand, Sacrifice Martyr of Frost: Counter target spell unless its controller pays {X}.

Snow-Covered Island

Rootwater Hunter

{T}: Rootwater Hunter deals 1 damage to any target.

Merfolk Looter

Rage of Winter

Tap target creature. It doesn't untap during its controller's next untap step. (Then exile this card. You may cast the creature later from exile.)

Queen of Ice

Whenever Queen of Ice deals combat damage to a creature, tap that creature. It doesn't untap during its controller's next untap step.

Queen of Ice // Rage of Winter

Disruptive Pitmage

{T}: Counter target spell unless its controller pays {1}.
Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Stonybrook Banneret

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Merfolk spells and Wizard spells you cast cost {1} less to cast.

Whirlpool Rider

When Whirlpool Rider enters, shuffle the cards from your hand into your library, then draw that many cards.

Desert

{T}: Add {C}.
{T}: Desert deals 1 damage to target attacking creature. Activate only during the end of combat step.

Tidal Warrior

{T}: Target land becomes an Island until end of turn.

Rimewind Taskmage

{1}, {T}: You may tap or untap target permanent. Activate only if you control four or more snow permanents.

Drowner Initiate

Whenever a player casts a blue spell, you may pay {1}. If you do, target player mills two cards.

Watertrap Weaver

When Watertrap Weaver enters, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Sage's Row Denizen

Whenever another blue creature you control enters, target player mills two cards.

Razorfin Hunter

{T}: Razorfin Hunter deals 1 damage to any target.

Stream of Unconsciousness

Target creature gets -4/-0 until end of turn. If you control a Wizard, draw a card.

Distant Melody

Choose a creature type. Draw a card for each permanent you control of that type.

Sidisi's Faithful

Exploit (When this creature enters, you may sacrifice a creature.)
When Sidisi's Faithful exploits a creature, return target creature to its owner's hand.

Waterfront Bouncer

{U}, {T}, Discard a card: Return target creature to its owner's hand.

Spellstutter Sprite

Flash
Flying
When Spellstutter Sprite enters, counter target spell with mana value X or less, where X is the number of Faeries you control.

Silvergill Douser

{T}: Target creature gets -X/-0 until end of turn, where X is the number of Merfolk and/or Faeries 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.)

Deranged Assistant

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Venture Deeper

Target player mills four cards. (Then exile this card. You may cast the creature later from exile.)