Scarim Coral said:
So is Soul Edge is like the new Ganon. It seems no matter how much it claims that Soul Edge get destroyed from the last game, it appear again in the next.
Exactly how it's always been! Soul Edge is enchanted with pure metaphysical plot magic bullshit, that allows it to fade in and out of existence/memory whenever it is convenient for not getting permanently destroyed and for surprising the complacent Disney-like peace of the world after it is gone... And I wouldn't have it any other way.

just kidding.
Aside from that, story is irrelevant in fighting games, because their game-play style demands that the developers spend as much time as possible trying to balance the fighters techniques against each other, while still holding their own sense of individuality, which makes anything but the most extensive play-testing endeavors fail. Having spent their entire budget and schedule on this, they have to cobble together a cheap setting and motivation for their characters, that often reads like a fanfic, and may in fact be a total ripoff from a quick Google search.
But that's just me talking, I know jackshit about game development, so don't take my word for it! Lol!