Quote Originally Posted by PuPu View Post
Sephiroth's source of power is Jenova AND the Lifestream. Lifestream is the source of all magic and life in the world of FFVII, and Sephiroth actually suceeded in controlling it, in AC.
He managed to give Geostigma to some children. If he really managed to control all of Lifestream, Cloud wouldn't have been able to stop him, and Seph would have already won. But I would agree that he controlled maybe at least half of Lifestream, but not all.
Aeris probably controlled enough to keep Sephiroth beatable. But Kefka didn't have a monopoly of magic either, so they're most likely even in terms of power.

Well, this is only your opinion, and I will give my: I would say that if we give prep to them Kefka could win, but in a direct combat Sephiroth would be the winner.
Kefka does have more power than Sephiroth, but yeah, Seph would definitely rip Kefka to shreds with his sword. After all, power doesn't necessarily determines who would win a fight.
And if Kefka was foolish enough to engage the Returners in direct combat rather than smite them from afar, there's no reason why he wouldn't do the same against Sephiroth.

Avalanche are much better fighters than the Returners. AC and DoC proves that.
Isn't this also an opinion as well, since you have yet to actually explain what this "proof" is?
They took down that big freakin' dragon. I didn't see the Returners do anything even remotely as impressive.

And I don't know about DoC, but Avalanche didn't really seem to do much in AC. Avalanche beat a few monsters. Cloud was the one who actually defeated Kadaj, Yazoo, Loz, Bahamut, and Sephiroth.
Aeris defeated Yazoo and Loz, iirc. Cloud used the other seven as launching pads for his fatal strike on Bahamut.

And Kefka having the higher level of power is just opinion. In my opinion, using the corrupted version of the source of magic in the world, to transform the planet in a dead vessel and use it to travell the universe, is much more impressive than destroying some cities with a light from the sky.
And terrorizing the world for many years is more impressive than infecting a few children with Geostigma.
Many years? It was just one. And infecting people with Geostigma was not Seph's ultimate ability.