What if Ramsey resurrected the Magpie's Wing in much the same form as the Burning Blade? (In lore, the Magpie's Wing was only a galleon, that's why I call it the Risen Magpie's Wing in the title)
It could be manned by phantoms instead of skellies, but otherwise function similarly. Maybe a different kind of front projectile and phantom-callers, but otherwise comparable.
I'm thinking they would need to be fairly similar for the next part of this... diving into battle against the opposing ship, much like in Hourglass. If a player-controlled opponent cannot be found, the matchmaking would fall back on a beefed-up AI version (i.e. more difficult than the current world event).
Unlike Hourglass, this would take place on an Arena-like self-contained server (no other ships or events, for performance reasons) and after the battle you would merge back to an Adventure server with your spoils.
Defeating the enemy would gain you their Burning Blade of Souls/Sword of Souls loaded with maybe 5 rituals, as well as giving a large chunk of Allegiance for your faction.
Discuss and drop any wild ideas for how this could function below!
Obviously, this is very much wishful thinking and heavily dependent on optimisations to allow both ships on the same server.
EDIT
There's a little bit of feedback on this, so I'll just add an addendum.
"Why not call it the Athena's Fortune?"
Yep, I had considered this up to a couple of minutes before posting, but the change to Magpie's Wing is purely to distinguish it. We already have Athena's Fortune the place (bar) and the faction, so I feel it's a bit over-used. I'm not against the idea, but maybe a variation? Such as The Glory of Athena's Fortune or something like that?
"Why Arena-like servers?"
That was a comparison point only, I'm not arguing for the return of Arena, I promise. My bad, a better comparison would probably have been the Sea of the Damned - a self contained small area. I said Arena-like because I think it should still take place in the Sea of Thieves, but a smaller area of the map which would have a boundary like in Arena or Hourglass.
Additional thoughts
I've been thinking about how to make sure the fight doesn't go on forever because of a running ship, which is a major downside of Hourglass. I imagine some kind of central Ancient anomaly which would change colour to indicate the winning side (Reaper red or Athena bluey green).
Who is winning would be determined by skellies/phantoms still alive/in reserve as well as damage done to opponent. The battle area would shrink slowly towards the anomaly and, after a period of time, if not already sunk, the losing ship would be struck down. Their flag, sword, and any loot, would be placed on the victor's ship in the hold automatically, before merging the ship out to an Adventure server.
I'm sure this could be fine-tuned so, again, please discuss.