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

Whenever equipped creature deals combat damage to a player, look at the top card of their library, then exile it face down. For as long as it remains exiled, you may play it, and mana of any type can be spent to cast that spell.
Equip

Kicker (You may pay an additional as you cast this spell.)
Flying
When this creature enters, destroy all lands you control. If it was kicked, destroy all lands instead.

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.
Cycling (, Discard this card: Draw a card.)

When this Spacecraft enters, destroy target noncreature permanent. Then this Spacecraft deals 4 damage to each creature.
Station (Tap another creature you control: Put charge counters equal to its power on this Spacecraft. Station only as a sorcery. It's an artifact creature at 5+.)
5+ | Flying, trample

Flying, trample
When Roalesk enters, put two +1/+1 counters on another target creature you control.
When Roalesk dies, proliferate, then proliferate again. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

If an opponent controls more lands than you, search your library for up to three Plains cards, reveal them, put them into your hand, then shuffle.

Bestow (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
This creature and enchanted creature each get +X/+X, where X is the number of creature cards in all graveyards.

Trample

All artifacts have "At the beginning of your upkeep, sacrifice this artifact unless you pay ."

Each player draws X cards.

Haste
, : Add . Spend this mana only to cast instant and/or sorcery spells.
When Cormela dies, return up to one target instant or sorcery card from your graveyard to your hand.

First strike
At the beginning of each upkeep, if no spells were cast last turn, transform this creature.

Flying
Whenever Treva deals combat damage to a player, you may pay . If you do, choose a color, then you gain 1 life for each permanent of that color.

This spell costs less to cast, where X is the total mana value of noncreature artifacts you control.
Sacrifice two artifacts: Return this card from your graveyard to your hand.

When this enchantment enters and at the beginning of your upkeep, you lose 1 life and create a Clue token. (It's an artifact with ", Sacrifice this token: Draw a card.")
Whenever you attack, put X +1/+1 counters on target attacking creature, where X is the number of permanents you've sacrificed this turn. If X is three or more, that creature gains lifelink until end of turn.

: Gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn. Activate only as a sorcery.

This land enters tapped.
When this land enters, exile target player's graveyard.
: Add .

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

As this creature enters, choose a word with four or more letters.
Spells with the chosen word in their text box can't be cast.