Gemstone Mine

Gemstone Mine enters with three mining counters on it.
{T}, Remove a mining counter from Gemstone Mine: Add one mana of any color. If there are no mining counters on Gemstone Mine, sacrifice it.

Daze

You may return an Island you control to its owner's hand rather than pay this spell's mana cost.
Counter target spell unless its controller pays {1}.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Rootwater Thief

{U}: Rootwater Thief gains flying until end of turn.
Whenever Rootwater Thief deals combat damage to a player, you may pay {2}. If you do, search that player's library for a card and exile it, then the player shuffles.

Lord of Atlantis

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

City of Brass

Whenever City of Brass becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

Fire

Fire deals 2 damage divided as you choose among one or two targets.

Fire // Ice

Winter Orb

As long as Winter Orb is untapped, players can't untap more than one land during their untap steps.

Vodalian Merchant

When Vodalian Merchant enters, draw a card, then discard a card.

Counterspell

Merfolk Looter

Tidal Warrior

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

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.