[member="Seris Vant"],
Yeah the third side are people like me or Muad Dib who don't want to follow either Ra, his Death Watch lackeys, and the new laws they're passing or Mia. To be fair though, the reason why HK right now would not follow Mia is not because he sees her as a rebel or terrorist, since like Ra she used to be the Mand'alore in the past and declared herself one now so as far as he's concerned until the war is over and one of them is dead she has as much claim to the title as Ra, but because she was the one behind the Mandalore Cataclysm in which earthquakes were triggered by a supervolcanoe explosion so he would want her face justice before anything else.
And the WMD thing, OOCly that wasn't Mia's doing but someone claiming to be on her side going a bit rogue, ICly HK doesn't even know about it going on, but there's something similar with Ra's forces and at least one squad of them being almost entirely really young child soldiers, which I personally find pretty find more than a bit disturbing especially if I'll end up being one of the people who has to fight them, but just like in Mia's case that wasn't his idea, in fact Ra told them to get to safety if I remember right, it's other writers choices.
As to the third side in this, one that I came to call Mando'ade, like Ra said it's pretty much the rest that is just caught in the middle of all this with different motivations and goals, for example HK just wants to get any civilians of Mandos who do not want to participate in the war out of the combat to just wait it out without backing either side, others like Muad decided to take a more active role and kind of screw both sides.