I normally dont get into this kind of discussion, but as its been pointed out, FFVII characters abilities were extremely superhuman, especially by the time AC happens. FFVIII are normal people with either military or martial arts training, and would stand no chance against any of the characters of FFVII, let alone the big bad boss Sephiroth.

Now then, Kuja vs Sephiroth is a fight I'd love to see, but *opens the door for a real discussion*, Kefka would pwn them all.... hes Kefka