Hitokiri no Final Fantasy (Movie or Game) has to do anything with a previous series. Well, thats untill they made FFX-2. By the way, when you think about it FF: TSW was similar to FFVII. (The planet dying, the life stream, only they didn't call it a life stream in the movie, and there was a buggy/jeep that they were riding on, you obtain a buggy to cross deserts and some rivers in FFVII arounds the middle of Disk 1 or somethin'). Also if I remember correctly the Alien Life Forms came to earth kinda like how Jenovah. And the fiends are born from that life energy I think.