Well, there was no turning back now.  Spinel was hoping that Carnelian would be able to lead the creature to her tower with as little interference as possible, so that the gem it had caught would have a place to land if she shot it down.  Thanks to Reggie's attack, it looked like the monster would likely be going down soon enough anyway.  Spinel aimed her crossbow at the creature's other wing and fired, hoping this would finish the job, and that maybe Chalcopyrite would be able to land in the tower with her from this distance.