When Cenote Scout enters the battlefield, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Whenever another Merfolk enters the battlefield under your control, put a +1/+1 counter on target Merfolk you control.

Tap another untapped Merfolk you control: Kumena, Tyrant of Orazca can't be blocked this turn. Tap three untapped Merfolk you control: Draw a card. Tap five untapped Merfolk you control: Put a +1/+1 counter on each Merfolk you control.

{W/U}, {Q}: Look at the top card of your library. You may exile that card. ({Q} is the untap symbol.)

When Thassa's Oracle enters the battlefield, look at the top X cards of your library, where X is your devotion to blue. Put up to one of them on top of your library and the rest on the bottom of your library in a random order. If X is greater than or equal to the number of cards in your library, you win the game. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Whenever one or more nontoken Merfolk you control become tapped, create a 1/1 blue Merfolk creature token with hexproof.

Look at the top six cards of your library. Put up to two creature cards with mana value 3 or less from among them onto the battlefield. Put the rest on the bottom of your library in any order.

Counter target noncreature spell unless its controller pays {2}.

Botanical Sanctum enters the battlefield tapped unless you control two or fewer other lands. {T}: Add {G} or {U}.

({T}: Add {G} or {U}.) As Breeding Pool enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

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

({T}: Add {U}.)

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

You may exile two blue cards from your hand rather than pay this spell's mana cost. Gain control of target noncreature spell. You may choose new targets for it. (If that spell is an artifact, enchantment, or planeswalker, the permanent enters the battlefield under your control.)

Sunburst (This enters the battlefield with a charge counter on it for each color of mana spent to cast it.) {2}, Sacrifice Engineered Explosives: Destroy each nonland permanent with mana value equal to the number of charge counters on Engineered Explosives.

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.)

If it's not your turn, you may exile a blue card from your hand rather than pay this spell's mana cost. Counter target noncreature spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Flash Flying When Subtlety enters the battlefield, choose up to one target creature spell or planeswalker spell. Its owner puts it on the top or bottom of their library. Evoke—Exile a blue card from your hand.