Force of Will

You may pay 1 life and remove a blue card in your hand from the game instead of paying Force of Will's casting cost. Effects that prevent or redirect damage cannot be used to counter this loss of life. Counter target spell.

Cavern of Souls

As Cavern of Souls enters the battlefield, choose a creature type. {T}: Add {1} to your mana pool. {T}: Add one mana of any color to your mana pool. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Master of the Pearl Trident

Other Merfolk creatures you control get +1/+1 and have islandwalk. (They are unblockable as long as defending player controls an Island.)

Daze

You may return an island you control to its owner's hand instead of paying Daze's mana cost. Counter target spell unless its controller pays {1}.

Mental Misstep

({U/P} can be paid with either {U} or 2 life.) Counter target spell with converted mana cost 1.

Flusterstorm

Counter target instant or sorcery spell unless its controller pays {1}. Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Sylvan Library

You may draw two extra cards during your draw phase. If you do so, put two of the cards drawn this turn back on top of your library (in any order) or pay 4 life per card not replaced. Effects that prevent or redirect damage cannot be used to counter this loss of life.

Cursecatcher

Sacrifice Cursecatcher: Counter target instant or sorcery spell unless its controller pays {1}.

Mox Emerald

Add 1 green mana to your mana pool. Tapping this artifact can be played as an interrupt.

Mox Sapphire

Add 1 blue mana to your mana pool. Tapping this artifact can be played as an interrupt.

Lord of Atlantis

All Merfolk in play gain islandwalk and +1/+1 while this card is in play.

Time Walk

Take an extra turn after this one.

Tropical Island

Counts as both forest and islands and is affected by spells that affect either. Tap to add either {G} or {U} to your mana pool.

Ancestral Recall

Draw 3 cards or force opponent to draw 3 cards.

Black Lotus

Adds 3 mana of any single color of your choice to your mana pool, then is discarded. Tapping this artifact can be played as an interrupt.

Null Rod

Players cannot play any artifact abilities requiring an activation cost.

Ravenous Trap

If an opponent had three or more cards put into his or her graveyard from anywhere this turn, you may pay {0} rather than pay Ravenous Trap's mana cost. Exile all cards from target player's graveyard.

Flooded Strand

Polluted Delta

Strip Mine

Wasteland

Kumena's Speaker

G

Merfolk Branchwalker

1G

Spell Pierce

U

Silvergill Adept

As an additional cost to cast this spell, reveal a Merfolk card from your hand or pay {3}. When Silvergill Adept enters the battlefield, draw a card.

Island

({T}: Add {U}.)