Theories concerning the origins of LV 4 Limit Techniques...

[Gym Leader Devil]

The only problems I'd have with the Zack's Omnislash theory is are:

1) If he wrote a manual on it, his name would have been on it somewhere Unless it was just a rough draft he had scribbled in a spiral notebook laying on his coffee table or something.

2) Omnislash (the original) is similar enough to two of Zack's other limit breaks from CC -- Octaslash and Chain Slash -- that it doesn't make very much sense to say he didn't or couldn't master the technique and use it. Zack had years of training and practice as a swordsman, and if he was able to design it and write it down, possibly with diagrams, and make it understandable enough for someone like Cloud to understand it and master it, why wouldn't Zack himself have used it?

I have no means of countering the lack of a signature on the manual if Zack wrote it, not really. As for your other point, Omnislash is somewhat similar to other techniques Zack used, I feel this lends credence to him developing his own technique based on the experience of using those, just as Cloud developed it further into Omnislash Version 5/6. As to why he didn't use it himself: In ACC did you notice how freaking huge the wave of energy Cloud gives off right before attempting the original Omnislash on Sephylis is? It's significantly larger than what his other limits give off. Maybe Zack never managed to put out this much spirit energy, or refined his use of said energy to use it properly in this instance. I know in my own life, I've been practicing swordplay of various kinds for a long time (though I naturally lack the life or death experience Zack has) and have developed a technique of my own... can't use it effectively yet though, not enough practical practice.

To play Devil's Advocate against my own point, maybe Cloud was just more pissed than usual at that moment I mentioned.

Otherwise, I love all the theories for the other characters. I think I especially like Cid's, because it makes a ton of sense in his own storyline.

Thanks, and yes Highwind and Final Heaven are my favorites.