Lookout's Dispersal

This spell costs {1} less to cast if you control a Pirate.
Counter target spell unless its controller pays {4}.

Curious Obsession

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, you may draw a card."
At the beginning of your end step, if you didn't attack with a creature this turn, sacrifice this Aura.

Kitesail Freebooter

Flying
When this creature enters, target opponent reveals their hand. You choose a noncreature, nonland card from it. Exile that card until this creature leaves the battlefield.

Lofty Denial

Counter target spell unless its controller pays {1}. If you control a creature with flying, counter that spell unless its controller pays {4} instead.

Drowned Catacomb

This land enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Siren Stormtamer

Flying
{U}, Sacrifice this creature: Counter target spell or ability that targets you or a creature you control.

Kitesail Corsair

This creature has flying as long as it's attacking.

Swamp

Lost Legacy

Choose a nonartifact, nonland card name. Search target player's graveyard, hand, and library for any number of cards with that name and exile them. That player shuffles, then draws a card for each card exiled from their hand this way.

Scavenger Grounds

{T}: Add {C}.
{2}, {T}, Sacrifice a Desert: Exile all graveyards.

Dreamcaller Siren

Flash
Flying
This creature can block only creatures with flying.
When this creature enters, if you control another Pirate, tap up to two target nonland permanents.

Warkite Marauder

Flying
Whenever this creature attacks, target creature defending player controls loses all abilities and has base power and toughness 0/1 until end of turn.

Nezahal, Primal Tide

This spell can't be countered.
You have no maximum hand size.
Whenever an opponent casts a noncreature spell, draw a card.
Discard three cards: Exile Nezahal. Return it to the battlefield tapped under its owner's control at the beginning of the next end step.

Walk the Plank

Island

Jace, Cunning Castaway

+1: Whenever one or more creatures you control deal combat damage to a player this turn, draw a card, then discard a card.
−2: Create a 2/2 blue Illusion creature token with "When this token becomes the target of a spell, sacrifice it."
−5: Create two tokens that are copies of Jace, except they're not legendary.