Quote Originally Posted by Mo-Nercy View Post
I suppose that X and X-2 would lead into VII. The fact that there's a kid named Shinra in X-2 who briefly mentions something about harvesting the Farplane as an energy source (reminiscent of Mako and the Lifestream) seems to suggest as much.
That's the idea. There is not more than that when it comes to canonical thoughts and facts however except some substances being the same.

Since Final Fantasy XIII has a lifestream ...

Well, only VII and X and XIII and XV are connected. The rest exists as multiverse/different dimensions seperated from those that is travelled through the rift by Gilgamesh to collect swords as Final Fantasy XII says. That is more a gag connection, however. It being a multiverse is not even officially stated, but Gilgameshs entry is at least an explanation.