Back to the Op , Disney's Pirate's of the Carribean + Sea of Thieves was an amazing Idea wonder what other pirate cross will Microsoft do?
Vampire Coast pirates from Total Warhammer II. I mean it's literally vampire pirates on a quest for a legendary magical harpoon to slay a massive sea creature while looting, pillaging, and sucking blood from victims along the way.
Captain Hook, Peter pan, and gang would be cool. Make Neverland the island it is based around in this expansion.