Special mention must also go to the soundtrack. Never has remixed classical music been so terrifying.Here, have a listen.
Furiae in Ending B when she's "reborn." The page image.
Ending B in general is a massive horror show. Not only does Caim have to fight an insane Furiae reborn as a weird angel hybrid, but what comes afterward is even worse. After an incredibly tough battle Caim holds a now deceased Furiae, and can only grimly watch as countless clones of the angel Furiae rise from the ground screaming in agony. Keep in mind that Caim was only barely able to defeat the original Furiae, and the thought of fighting a horde of them makes it clear that Caim and humanity as a whole are doomed.