Starkiller would actively attempt to kill it, seeing it as a threat, but will be promptly sick and unable to use the Force appropriately so he can get his ass kicked a bit.
Pyro will be focused on keeping Kitty safe. If people are around to keep safe as collateral, he will help them. But he's selfish and cares for one. If he uses his abilities to throw fire around, it would be wildly uncontrolled.
Nyx is perfectly healthy and will be doing everything to help and keep Moony busy. All his attacks would be as nonlethal as he can. So he wouldn't cut him or use dangerous magic on him. He would more likely take a hit for a person than allow them to get hurt. Frost saw the movie he's from, so she can possibly consult on his warping and being annoying towards the werewolf. Every time he sees Ritsu, he will tell him to go home and lock the doors. Full permission to hurt Nyx as much as you want. :D