weren't they a separate species from the beginning? but they became so detached form the world that they even perceived humanity as scenery. and they didn't even talk, because they didn't see the need for it(telepathy with their own kind was all that they needed). and Eve (the black haired one, the "mother" of all current seraphs) was one of them, still a child at that time and only one that still talked. I can't remember it precisely, but I think she was the sole survivor. and later she made new seraphs.
feel free to correct me if I am wrong ╮(￣▽￣)╭
Yeah I'm not too sure myself - I did think they were another species at first but then they also seemed like experimental subjects?
If someone knows, do enlighten us please!
Huh - so those people with shortened life spans and deranged looking, they were one of the first experimental subjects right? Were the seraphs also experimental subjects ? Is that how they came into existence ?