Sigil Tracer

{1}{U}, Tap two untapped Wizards you control: Copy target instant or sorcery spell. You may choose new targets for the copy.

Sea Scryer

Intrepid Hero

{T}: Destroy target creature with power 4 or greater.

Tempest Drake

Graceful Reprieve

When target creature dies this turn, return that card to the battlefield under its owner's control.

Manta Riders

{U}: Manta Riders gains flying until end of turn.

Sunken City

At the beginning of your upkeep, sacrifice Sunken City unless you pay {U}{U}.
Blue creatures get +1/+1.

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.

Goldmeadow Harrier

Ambassador Laquatus

Sage of Fables

Each other Wizard creature you control enters with an additional +1/+1 counter on it.
{2}, Remove a +1/+1 counter from a creature you control: Draw a card.

Dimir Guildgate

This land enters tapped.
{T}: Add {U} or {B}.

Plains

Judge of Currents

Whenever a Merfolk you control becomes tapped, you may gain 1 life.

Vodalian Soldiers

Island

Phantasmal Terrain

Enchant land
As Phantasmal Terrain enters, choose a basic land type.
Enchanted land is the chosen type.

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.

Stonybrook Schoolmaster

Whenever Stonybrook Schoolmaster becomes tapped, you may create a 1/1 blue Merfolk Wizard creature token.

Spirit Loop

Enchant creature you control
Whenever enchanted creature deals damage, you gain that much life.
When Spirit Loop is put into a graveyard from the battlefield, return Spirit Loop to its owner's hand.

Counterspell

Grimoire Thief

Whenever Grimoire Thief becomes tapped, exile the top three cards of target opponent's library face down.
You may look at cards exiled with Grimoire Thief.
{U}, Sacrifice Grimoire Thief: Turn all cards exiled with Grimoire Thief face up. Counter all spells with those names.

Vodalian Knights

First strike
Vodalian Knights can't attack unless defending player controls an Island.
When you control no Islands, sacrifice Vodalian Knights.
{U}: Vodalian Knights gains flying until end of turn.

War Barge

{3}: Target creature gains islandwalk until end of turn. When War Barge leaves the battlefield this turn, destroy that creature. A creature destroyed this way can't be regenerated. (A creature with islandwalk can't be blocked as long as defending player controls an Island.)

Merfolk Assassin

{T}: Destroy target creature with islandwalk.

Harpoon Sniper

{W}, {T}: Harpoon Sniper deals X damage to target attacking or blocking creature, where X is the number of Merfolk you control.

Merrow Witsniper

When Merrow Witsniper enters, target player mills a card.

Mothdust Changeling

Changeling (This card is every creature type.)
Tap an untapped creature you control: Mothdust Changeling gains flying until end of turn.

Galina's Knight

Avian Changeling

Changeling (This card is every creature type.)
Flying

Lord of Atlantis

Other Merfolk get +1/+1 and have islandwalk. (They can't be blocked as long as defending player controls an Island.)

Soratami Mirror-Guard

Flying
{2}, Return a land you control to its owner's hand: Target creature with power 2 or less can't be blocked this turn.