Water Elemental

Unsummon

Return target creature to its owner's hand.

Drain Power

Target player activates a mana ability of each land they control. Then that player loses all unspent mana and you add the mana lost this way.

Giant Tortoise

Giant Tortoise gets +0/+3 as long as it's untapped.

Phantasmal Terrain

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

Mana Short

Tap all lands target player controls and that player loses all unspent mana.

Zephyr Falcon

Mahamoti Djinn

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

Ankh of Mishra

Whenever a land enters, Ankh of Mishra deals 2 damage to that land's controller.

Flood

{U}{U}: Tap target creature without flying.

Ghost Ship

Sindbad

{T}: Draw a card and reveal it. If it isn't a land card, discard it.

Air Elemental

Sea Serpent

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

Stasis

Players skip their untap steps.
At the beginning of your upkeep, sacrifice Stasis unless you pay {U}.

Pirate Ship

Pirate Ship can't attack unless defending player controls an Island.
{T}: Pirate Ship deals 1 damage to any target.
When you control no Islands, sacrifice Pirate Ship.

Sunken City

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