OK, I'm totally not claiming this *means* anything, I'm just pointing out some amusing parallels I thought of when replaying through FF7:
Ancients/Nonmen (old race destroyed by virus from alien threat)
Jenova/Inchoroi (alien threat in fantasy world)
Cloud-Zack/Drusas-Seswatha (protagonist with hidden personality)
Sephiroth/Kellhus (villain is engineered super powerful warrior/mage that goes insane)
Meteor Summoning / Revival of the No-God (world-ending threat brought about by villain)
How about it!