Spreading Seas

Enchant land
When Spreading Seas enters the battlefield, draw a card.
Enchanted land is an Island.

Annex

Enchant land (Target a land as you cast this. This card enters the battlefield attached to that land.)
You control enchanted land.

Threads of Disloyalty

Enchant creature with mana value 2 or less
You control enchanted creature.

Boomerang

Return target permanent to its owner's hand.

Faerie Conclave

Faerie Conclave enters the battlefield tapped.
{T}: Add {U}.
{1}{U}: Faerie Conclave becomes a 2/1 blue Faerie creature with flying until end of turn. It's still a land.

Island

Squelch

Counter target activated ability. (Mana abilities can't be targeted.)
Draw a card.

Piracy Charm

Choose one —
• Target creature gains islandwalk until end of turn. (It can't be blocked as long as defending player controls an Island.)
• Target creature gets +2/-1 until end of turn.
• Target player discards a card.

Gemstone Caverns

If Gemstone Caverns is in your opening hand and you're not the starting player, you may begin the game with Gemstone Caverns on the battlefield with a luck counter on it. If you do, exile a card from your hand.
{T}: Add {C}. If Gemstone Caverns has a luck counter on it, instead add one mana of any color.

Sea's Claim

Enchant land (Target a land as you cast this. This card enters the battlefield attached to that land.)
Enchanted land is an Island.

Master of Waves

Protection from red
Elemental creatures you control get +1/+1.
When Master of Waves enters the battlefield, create a number of 1/0 blue Elemental creature tokens equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Venser, Shaper Savant

Flash
When Venser, Shaper Savant enters the battlefield, return target spell or permanent to its owner's hand.

Encroaching Wastes

{T}: Add {C}.
{4}, {T}, Sacrifice Encroaching Wastes: Destroy target nonbasic land.

Frost Titan

Whenever Frost Titan becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {2}.
Whenever Frost Titan enters the battlefield or attacks, tap target permanent. It doesn't untap during its controller's next untap step.

Convincing Mirage

Enchant land
As Convincing Mirage enters the battlefield, choose a basic land type.
Enchanted land is the chosen type.