2. Sounds fun! Maybe this will all tie into with the Threat's sudden appearance. Maybe not just a freak cosmic storm but a dimensional disturbance? Something like that.

6. You know the Hunters, from Halo? How they aren't really one organism, but rather a collection of different organisms to make up one operating semi-intelligent being? What if it was like that? 

7. "Teams up". Well,  what do you mean by that? Fighting side by side, or just, the bounty hunter just is a huge prick and starts picking off soldiers? Maybe not a bounty hunter, but a commando from a rival army or something.

8. That depends. If this Oryu planet isn't TOO important, I don't see why the Threat shouldn't be able to just take it over completely and make it into it's own creepy mushy dominion. If you want to keep it in your own head canon, we could just have the heroes retreat from this scary massive monster. If you want to have a little side-canon, we could just have some of them die in the battle. Maybe in future battles, this Threat infested Oryu planet could be a location to fight on, or an established location in the lore.