Plundering Pirate

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

Waylaying Pirates

When Waylaying Pirates enters, if you control an artifact, tap target artifact or creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Shipwreck Sentry

Defender
As long as an artifact entered the battlefield under your control this turn, Shipwreck Sentry can attack as though it didn't have defender.

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.)

Captain Storm, Cosmium Raider

Whenever an artifact you control enters, put a +1/+1 counter on target Pirate you control.

Goblin Tomb Raider

As long as you control an artifact, Goblin Tomb Raider gets +1/+0 and has haste.

Brazen Blademaster

Whenever Brazen Blademaster attacks while you control two or more artifacts, it gets +2/+1 until end of turn.