I just got this brilliant idea that would make the story have more than one part. The Nero and Weiss would work but what about Hojo and Lucrecia?
Lucrecia was the mother of Sephiroth, she must've been strong, right?
Hojo was the father of Sephiroth, he doesn't have a strong soul but maybe he used his intelligence to make Emerald weapon absorb him in hope of taking control over it.
Would that work, like at all? :O