First, I want to say again that Pyron would crush them easily. With this post, I'm NOT saying that Sephiroth could win this battle.
But...
While visiting this forum, not logged, I saw something so ridiculous and wrong that I have to intervene. I'm talking about Nikk trying to explain what happens in FFVII, to anyone else(Becci in this case).
Becci... Pyron_Kinght knows shit about FFVII, and is a FFVII-hater who use the little he knows to bash and underrate the game and it's characters everytime he can.
So Becci, forget what he said about Sephiroth not absorbing Mako/Lifestream. Hell, forget everything he said about FFVII.
Now, to destroy his "argument"...
Sephiroth's quote at the Temple of the Ancients:
I became a traveler of the Lifestream and gained the knowledge and wisdom of the Ancients.
To anyone who doesn't know, the "knowledge and wisdom of the Ancients" is within Materia(that is condensed Mako/Lifestream).
And a translation of "The Maiden who Travels the Planet", a book released by S-E:
Chapter 7Cloud and his companions defeated Sephiroth.
Sinking into the Planet's scar and absorbing the Mako energy, the original Sephiroth was revived with his wounds fully healed. In the battle that unfolded afterwards, the will he inherited from Jenova, his own ambitions and the strong thoughts he had inside him granted him formidable power but, the humans still managed to crush him in the end. Sephiroth's physical body was destroyed and full of wounds, he retreated.
Here is a link to the translation:
http://one.xthost.info/ffwebnovel/
See Becci? PK's knowledge about FFVII is a joke. Forget what he said.