Seize the Spoils

As an additional cost to cast this spell, discard a card.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Crimson Fleet Commodore

Trample
When Crimson Fleet Commodore enters the battlefield, you become the monarch.

Azure Fleet Admiral

When Azure Fleet Admiral enters the battlefield, you become the monarch.
Azure Fleet Admiral can't be blocked by creatures the monarch controls.

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Breeches, Brazen Plunderer

Menace
Whenever one or more Pirates you control deal damage to your opponents, exile the top card of each of those opponents' libraries. You may play those cards this turn, and you may spend mana as though it were mana of any color to cast those spells.
Partner (You can have two commanders if both have partner.)

Chart a Course

Draw two cards. Then discard a card unless you attacked this turn.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Fire Diamond

Fire Diamond enters the battlefield tapped.
{T}: Add {R}.

The Autonomous Furnace

The Autonomous Furnace enters the battlefield tapped.
{T}: Add {R}.
{1}{R}, {T}, Sacrifice The Autonomous Furnace: Draw a card.

Curiosity

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Kessig Flamebreather

Whenever you cast a noncreature spell, Kessig Flamebreather deals 1 damage to each opponent.

Storm Fleet Sprinter

Haste
Storm Fleet Sprinter can't be blocked.

Coastline Marauders

Trample
Whenever Coastline Marauders attacks, it gets +1/+0 until end of turn for each land defending player controls.
Encore {4}{R}{R} ({4}{R}{R}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Cutthroat Negotiator

Parley — Whenever Cutthroat Negotiator attacks, each player reveals the top card of their library. For each nonland card revealed this way, you create a tapped Treasure token. Then each player draws a card.

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

Molten Tributary

({T}: Add {U} or {R}.)
Molten Tributary enters the battlefield tapped.

Captain Vargus Wrath

Whenever Captain Vargus Wrath attacks, Pirates you control get +1/+1 until end of turn for each time you've cast a commander from the command zone this game.

Lookout's Dispersal

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

Path of Ancestry

Path of Ancestry enters the battlefield tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Volatile Claws

Until end of turn, creatures you control get +2/+0 and gain all creature types.

Siren's Ruse

Exile target creature you control, then return that card to the battlefield under its owner's control. If a Pirate was exiled this way, draw a card.

Fiery Cannonade

Fiery Cannonade deals 2 damage to each non-Pirate creature.

Spectral Sailor

Flash (You may cast this spell any time you could cast an instant.)
Flying
{3}{U}: Draw a card.

Trove Tracker

When Trove Tracker dies, draw a card.
Encore {5}{U}{U} ({5}{U}{U}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Expedite

Target creature gains haste until end of turn.
Draw a card.

Daring Saboteur

{2}{U}: Daring Saboteur can't be blocked this turn.
Whenever Daring Saboteur deals combat damage to a player, you may draw a card. If you do, discard a card.

Deep Analysis

Target player draws two cards.
Flashback—{1}{U}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Fanatical Firebrand

Haste
{T}, Sacrifice Fanatical Firebrand: It deals 1 damage to any target.

Zara, Renegade Recruiter

Flying
Whenever Zara, Renegade Recruiter attacks, look at defending player's hand. You may put a creature card from it onto the battlefield under your control tapped and attacking that player or a planeswalker they control. Return that creature to its owner's hand at the beginning of the next end step.

Runed Stalactite

Equipped creature gets +1/+1 and is every creature type.
Equip {2}

Lightning-Rig Crew

{T}: Lightning-Rig Crew deals 1 damage to each opponent.
Whenever you cast a Pirate spell, untap Lightning-Rig Crew.

Kitesail Skirmisher

Flying
Whenever Kitesail Skirmisher attacks, another target creature attacking the same player or planeswalker gains flying until end of turn.
Encore {4}{U} ({4}{U}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Kitesail Corsair

Kitesail Corsair has flying as long as it's attacking.

Glint-Horn Buccaneer

Haste
Whenever you discard a card, Glint-Horn Buccaneer deals 1 damage to each opponent.
{1}{R}, Discard a card: Draw a card. Activate only if Glint-Horn Buccaneer is attacking.

Malcolm, Keen-Eyed Navigator

Flying
Whenever one or more Pirates you control deal damage to your opponents, you create a Treasure token for each opponent dealt damage. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Partner (You can have two commanders if both have partner.)

Swiftwater Cliffs

Swiftwater Cliffs enters the battlefield tapped.
When Swiftwater Cliffs enters the battlefield, you gain 1 life.
{T}: Add {U} or {R}.

Daring Piracy

At the beginning of combat on your turn, create a 1/1 red Pirate creature token with menace and haste. Exile it at the beginning of the next end step.

Arcane Signet

The Surgical Bay

The Surgical Bay enters the battlefield tapped.
{T}: Add {U}.
{1}{U}, {T}, Sacrifice The Surgical Bay: Draw a card.

Sailor of Means

When Sailor of Means enters the battlefield, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Mountain

Izzet Signet

Fathom Fleet Swordjack

Whenever Fathom Fleet Swordjack attacks, it deals damage to the player or planeswalker it's attacking equal to the number of artifacts you control.
Encore {5}{R} ({5}{R}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Flood of Recollection

Return target instant or sorcery card from your graveyard to your hand. Exile Flood of Recollection.

Aqueous Form

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Captain's Hook

Equipped creature gets +2/+0, has menace, and is a Pirate in addition to its other creature types.
Whenever Captain's Hook becomes unattached from a permanent, destroy that permanent.
Equip {1}

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Negate

Merchant Raiders

Whenever Merchant Raiders or another Pirate enters the battlefield under your control, tap up to one target creature. That creature doesn't untap during its controller's untap step for as long as you control Merchant Raiders.

Amorphous Axe

Equipped creature gets +3/+0 and is every creature type.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Boarding Party

Haste
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Burdened Aerialist

When Burdened Aerialist enters the battlefield, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Whenever you sacrifice a token, Burdened Aerialist gains flying until end of turn.

Ingenious Artillerist

Whenever one or more artifacts enter the battlefield under your control, Ingenious Artillerist deals that much damage to each opponent.

Zephyr Singer

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Flying, vigilance
When Zephyr Singer enters the battlefield, put a flying counter on each creature that convoked it.

Wings of Velis Vel

Changeling (This card is every creature type.)
Until end of turn, target creature has base power and toughness 4/4, gains all creature types, and gains flying.

Scour All Possibilities

Scry 2, then draw a card.
Flashback {4}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Blades of Velis Vel

Changeling (This card is every creature type.)
Up to two target creatures each get +2/+0 and gain all creature types until end of turn.

Coercive Recruiter

Whenever Coercive Recruiter or another Pirate enters the battlefield under your control, gain control of target creature until end of turn. Untap that creature. Until end of turn, it gains haste and becomes a Pirate in addition to its other types.

Trickery Charm

Choose one —
• Target creature gains flying until end of turn.
• Target creature becomes the creature type of your choice until end of turn.
• Look at the top four cards of your library, then put them back in any order.

Reckless Fireweaver

Whenever an artifact enters the battlefield under your control, Reckless Fireweaver deals 1 damage to each opponent.

Sky Diamond

Sky Diamond enters the battlefield tapped.
{T}: Add {U}.

Impulsive Pilferer

When Impulsive Pilferer dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Encore {3}{R} ({3}{R}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Goblin Trailblazer

Menace (This creature can't be blocked except by two or more creatures.)

Island

Izzet Charm

Choose one —
• Counter target noncreature spell unless its controller pays {2}.
• Izzet Charm deals 2 damage to target creature.
• Draw two cards, then discard two cards.

Sticky Fingers

Enchant creature
Enchanted creature has menace and "Whenever this creature deals combat damage to a player, create a Treasure token." (It can't be blocked except by two or more creatures. The token is an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
When enchanted creature dies, draw a card.

Siren Stormtamer

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

Prosperous Pirates

When Prosperous Pirates enters the battlefield, create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Pirate's Prize

Draw two cards. Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")