Level up
LEVEL 2-3|Flying|3/3
LEVEL 4+|Flying
Other merfolk creatures you control gets +1/+1|4/4

You may pay 1 life and exile a blue card from your hand rather than pay Force of Will's mana cost.
Counter target spell.

: Add to your mana pool.
: Mutavault becomes a 2/2 creature with all creature types until end of turn. It's still a land.

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

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

: Add to your mana pool.
, Sacrifice Wasteland: Destroy target nonbasic land.

Other Merfolk creatures you control get +1/+1.
Whenever you cast a Merfolk spell, you may tap or untap target permanent.

Other Merfolk creatures get +1/+1 and have islandwalk.

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

At the beginning of your upkeep, you may put a charge counter on Æther Vial.
: You may put a creature card with converted mana cost equal to the number of charge counters on Æther Vial from your hand onto the battlefield.

When a player casts a spell, sacrifice Standstill. If you do, each of that player's opponents draws three cards.

, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card and put it onto the battlefield. Then shuffle your library.

, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card and put it onto the battlefield. Then shuffle your library.

You may have Phantasmal Image enter the battlefield as a copy of any creature on the battlefield, except it's an Illusion in addition to its other types and it gains "When this creature becomes the target of a spell or ability, sacrifice it."

( can be paid with either or 2 life.)
Target creature gets -5/-5 until end of turn.

, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card and put it onto the battlefield. Then shuffle your library.

Flying
Creatures you control have "Whenever this creature becomes the target of a spell or ability for the first time in a turn, counter that spell or ability."

Flying
When Sower of Temptation enters the battlefield, gain control of target creature for as long as Sower of Temptation remains on the battlefield.

, Sacrifice Tormod's Crypt: Exile all cards from target player's graveyard.

As Pithing Needle enters the battlefield, name a card.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.

, Sacrifice Nihil Spellbomb: Exile all cards from target player's graveyard.
When Nihil Spellbomb is put into a graveyard from the battlefield, you may pay . If you do, draw a card.

Creature cards can't enter the battlefield from graveyards or libraries.
Players can't cast cards in graveyards or libraries.

Destroy all green creatures. They can't be regenerated.

If an opponent controls a Forest and you control an Island, you may cast Submerge without paying its mana cost.
Put target creature on top of its owner's library.

Choose one - Counter target spell if it's red; or destroy target permanent if it's red.

White creatures get -1/-1.