Lord of Atlantis

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

Serendib Efreet

Flying
At the beginning of your upkeep, Serendib Efreet deals 1 damage to you.

Juggernaut

This creature attacks each combat if able.
This creature can't be blocked by Walls.

Black Vise

As Black Vise enters, choose an opponent.
At the beginning of the chosen player's upkeep, Black Vise deals X damage to that player, where X is the number of cards in their hand minus 4.

Plains

Unsummon

Return target creature to its owner's hand.

Control Magic

Enchant creature
You control enchanted creature.

Braingeyser

Counterspell

Clone

You may have Clone enter as a copy of any creature on the battlefield.

Merfolk of the Pearl Trident

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Sea Serpent

Sea Serpent can't attack unless defending player controls an Island.
When you control no Islands, sacrifice Sea Serpent.

Sol Ring

Savannah Lions

Power Sink

Counter target spell unless its controller pays {X}. If that player doesn't, they tap all lands with mana abilities they control and lose all unspent mana.

Phantom Monster

Pearled Unicorn

Island

Disenchant

Mesa Pegasus

Flying; banding (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Air Elemental

Rod of Ruin

{3}, {T}: Rod of Ruin deals 1 damage to any target.

Samite Healer

{T}: Prevent the next 1 damage that would be dealt to any target this turn.

Phantasmal Terrain

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

Prodigal Sorcerer

{T}: Prodigal Sorcerer deals 1 damage to any target.

Mahamoti Djinn

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