Angrath's Marauders

If a source you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

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 in a random order.)

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.)

Storm Fleet Sprinter

Haste
Storm Fleet Sprinter can't be blocked.

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.

Marauding Looter

Raid — At the beginning of your end step, if you attacked this turn, you may draw a card. If you do, discard a card.

Protean Raider

Raid — If you attacked this turn, you may have Protean Raider enter as a copy of any creature on the battlefield.

Brazen Buccaneers

Haste
When Brazen Buccaneers enters, 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.)

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.

Brineborn Cutthroat

Flash (You may cast this spell any time you could cast an instant.)
Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on this creature.