Whatever happens, it won't be a fatal consequence for one of the main girls. Making that an unavoidable plot point would cause riots in the streets, and making it an avoidable plot point would mean having to write and render two versions of pretty much the entire remainder of the game. For that same reason, it likely won't be any real physical consequence either, though an unavoidable outcome where one of the girls gets attacked by something and ends up with a sick scar(probably Alex or Dalia, let's be real) could be possible.
If any girl is in mortal danger, it would probably be Calypso, who's not officially a main LI, but I would be skeptical of that happening to say the least - at least at this point in the game. End of 0.10 is an awkward place to stick a major character death if the game is going to be 13 updates long, in my eyes. So I think this being some life-threatening event is unlikely; even if a girl is badly wounded, there will be plot armor protecting them like Orion a couple episodes ago.