They're not after the sword. They can't be after the sword, for no less than half a dozen reasons. Some metagamey, some not.
Until they say the words 'Give us the sword', then they have to be after something else. In my mind. I could be wrong, it's happened before. But I don't think I am.
But, let's say you're right. Let's say that somehow, all these pirates have somehow missed what they came here to steal, come back up and demand our sword. Then I'll leave the situation to you, because you've obviously given it more thought than I. We may be screwed anyway, in that event, but that would definately be the time for a war of words.
Except, there MAY be another option. If they ARE here for the sword, we could say to them "Okay, but if you take the sword, then take me with it. Otherwise, we all die. You get what you want, you keep your people safe, and I keep my friends safe." That's what I think I would do. And if these pirates are somehow genuinely, magically, concerned about their victims, they might take us to Val Razua themselves. Or at least as close as they can get without someone giving them the barrage of cannon fire they deserve. Or maybe they could have other means at their disposal to find a cure. Maybe they'd even offer to make us part of the crew once we were better. This obviously isn't a tengu-only party, the mimic's a youkai. Guess they welcome anyone who's useful. And we would be useful.
Oy, there's a thought. Nazrin the pirate. NOT the direction I would have thought this game would take.
Either way, if I'm right, then we could be okay in the end. We'll be left with the sword, they'll be gone, and we'll be left with damage control from that stunt you pulled with the blood. But I have a lie prepared to cover that with our friends, since the truth didn't go all that well last time I tried it.
If you're right about the pirates, then I think you're prepared to deal with it. So we have all our bases covered.
All that's left now is to wait for Draco to surface, and we'll see which one of us is right.