Quote Originally Posted by KisaiTenshi View Post
They aren't fairytales, they are the parallel worlds. And the final boss may in fact be "Omega", but it won't go down in defeat, no it will likely escape and go into another parallel world, and thus it appears in FFXV next.
You may want to re-watch some cut scenes from deltascape. They actually do refer to one of the bosses as a fictional character from a story book.

While not likely to happen, having the next set actually be from a non FF game such as Chronotrigger would be cool and a big curveball to people.

Could you imagine running into...
Dragon Tank
Spekkio
Magus
Lavos

Or maybe the next set as groups of heroes from previous FF games.