Revive the Sea Dogs as a trading company with DeMarco's Ghost, Lesedi, and the other Sea Dogs NPCs that aren't members of the Dark Brethren. Have their main voyage be Gold Hoarder-esque with Sea Dog Chests as the loot, and have Sea Dog chests be marked on the map so that the PVP spirit of the Arena and the Sea Dogs is carried over into Adventure. Instead of earning gold, you earn silver from turning in loot, with silver being the currency used to buy cosmetics from the Sea Dogs company shop. Instead of having trading company NPCs at every outpost, they should be stationed exclusively on the Glorious Sea Dog Tavern, with that being the only turn-in point for loot.
Use the leftover, unreleased cosmetics from Arena, like the Fallen Sea Dog set, the various clothing items worn by Sea Dog NPCs, and the unreleased Silver Curse as the rewards to be earned. The Sea Dog sets were one of the nicest-looking cosmetic sets in-game. There should be reskins available to people who weren't around during Arena, with the Glorious and Triumphant Sea Dog sets kept exclusive to the pirates who earned them in the Arena.
