What about using creature type augmenting enchantments like Xenograft and Conspiracy to have stolen creatures become Pirates?

Have considered using Xenograft or Conspiracy to turn hostages into pirates?

SturmnDrang Well i know those effects , but I don't like them, it only works if you are ahead, otherwise their are just 5 mana enchantement do nothing, i'm not even using Arcane Adaptation that are the cheapest of those effect so i don't think I'll pay 5 mana for this.

Bazaar Trader keep what you steal for epic troll effect.

Mick-Tis I'm already keeping the permanent with the ability of my commander.

Unfortunatelly this guy is not a pirate and i don't have any stealing spell a part from the commander so I don't think it's worth it to run it in this deck.

I do use Bazaar Trader in my monored act of treason deck which is Mutiny is my Hobby where I need that effect, you might want to check it out.

To Mick-Tis Mea culpa I forgot about Captivating Crew,

which is probably why you suggest me Bazaar Trader, for short : -not a pirate , only enable 1 card in the deck. I think those 2 reason alone is sufficient to not run it.

Akujiki no worries, my version has a few give what you stole back at the end of turn. I Also play Arcane Adaptation to make everything a pirate

Here's my build so far if you're interested Privateer Beckett Brass (WIP)

Marionette Master is another good win condition. Looks like you’re staying away from counters but Lookout's Dispersal is a great counter for pirates, Spell Swindle and Hornswoggle are also good counters that also create treasure.

Jrm99

Marionette Master is not a pirate, but yes it's not a bad choice as win condition, i don't produce that much treasure to be worth it.

Spell Swindle was in the deck but only one counter isn't worth it to run, i've shyed away from counters because i want this deck to be mainly tribal and i don't think i'll run a worst negate that's already not that good in commander format.