Yeah, one of the things that made PSO's setting so interesting was that it felt a like the cosmic horror was mixed with Resident Evil-ish science horror a bit. 100% agree that most Darker enemies are monsters and people corrupted by D-Cells, with Falz itself prioritizing the strongest available that it needed to destroy psychologically rather than physically to make use of them as a host. Was really cool to be able to see some of that firsthand in PSP2i, including the side of her that's famous for being strong as hell when she took out the central dome dragon in one hit.
Though another thing that made the setting so memorable was that it had a very normal side on Pioneer 2, where almost no one has any idea any of that stuff is happening and just want to get married, or stake out land on Ragol and are antsy about why they're not allowed to go down there, or just want to know about the animals planetside. Probably one of the things that makes NGS's setting hard to get into is I have literally no idea what the average person wants or is even doing.