To be honest, to beat Orochi, Kyo needed help from both Iori and Chizuru...plus they were the living embodiment of his weaknesses/seal. Kind of like Kryptonite man fighting Superman.
the kryptonite thing is actually a fanmade theory. in the game itself and all the related info about it, it never explicity or even implicitly states that Orochi is weak against the kusanagi or yagami flames. all they said is that these were the flames that sealed Orochi all those years ago.
the kryptonite thing is a myth....just like the one that says Heihachi defeated Devil in T2. hachi never fought devil, never even came across him until Tekken4.
The following is the basic find and structure of what I have discovered.
-Kusanagi flames are normal ki flames without any gimmick. there is not even a single fact pointing to otherwise and if it is, I'm dying to know from all of you.
-the flames aren't kryptonite to Orochi either
-the Kusanagi clan specially devised techniques (along with Yasakani) to seal off the Orochi menace. to do this they formed a special fighting style that incorporated Chinese martial arts and pyro-techniques. both Yagami and Yasakani mastered and varied their techniques accordingly.
-Yasakani neutralizes, Kusanagi defeats and Yatta seals.A few centuries later, however, a certain change occurs in the families.
-the Yasakani's became the weakest of the three clans with the Kusanagi's the strongest, socially as well as in terms of power.
-jealous, the Yasakani clan made a blood pact with Orochi clan to turn the favor for themselves
-the Orochi gave the Yasakani GODLY powers but since the human body cannot contain such power, they have short life spans as their body withers away slowly.
-what they didn't know was that the Orochi could control them at any given time. any full blooded orochi can control the Yagami's. Probably the kof96 outburst of Iori that killed Vice and Mature was Goenitz's "going away present" since he did say "you'll see" before dying.
Their red flames became purple flames, didn't they?
WRONG.
As already stated the flames of Yasakani are Orochi flames. in-game evidence points to it with the fact that Orochi Chris and Iori's flames are the same. the Kusanagi and Yasakani both had the same flames, crimson. they weren't unique and it seems to me that this points against the much loved jobbing scenario (a lame theory put forward by retards that Orochi was sealed because the flames "weaken" him like Kryptonite to Superman).
But not only is there NO evidence given in any of the info on the ancient Orochi battle or the fact that the flames weaken Orochi. What we do know is that both the Yasakani and Kusanagi flames are one and the same, developed by both families together as they combined Chinese martial arts with the art of flame wielding. With the strongest son from each clan, they took on the Orochi and defeated it with their flames. The Yasakani merely neutralized Orochi while Kusanagi's defeated it....but the flames are both the same thing, that is, the pyro-techniques the clans mastered together. Years later the Orochi blood then combined with the Yasakani's and taught them the purple flame technique arts. They became Orochi flames after being taught.
It is generally believed by the fandom of KoF (and especially the Iori-Kyo retractors) that the flames are a genetic process where the person can naturally produce flames. But what DIRECTLY CONTRADICTS this is Iori's own quote: "I will never teach the Yagami flame techniques to anyone but a Yagami" in KoF: Kyo. But that is not all. To add to this is the fact that Shermie is one who taught Kyo's cousin, Aoi, the way of wielding purple flames. Aoi is NOT of Yagami blood nor was she ever tainted by the blood either. She doesn't even have any exposure to Orochi in the past either.
So its clear that one need not be a Yagami to wield the Yagami purple flames. As mentioned before, Iori's own quote proves it. Notice that all the Orochi's know how to wield purple flames (Shermie being one who taught Aoi Kusanagi) and Orochi Chris wielding them himself. But the purple flames can also be taught to anyone else. Hence purple flames are not a result of Orochi power, otherwise Aoi would not have been able to wield them since she is a pure breed Kusanagi.
So basically the Orochi blood mixed with that of the Yasakani's and after that they were taught the techniques of wielding purple flames, the same way Shermie taught Aoi the purple flames. The red flames didn't TURN purple. The Yasakani simply abandoned their red flames techniques for the newer purple flame techniques that the Orochi taught them.
Hence, the purple flames are simply a separate technique the Orochi's happen to know and master. It is independent of bloodline and Orochi power. This is why they are called Orochi flames: because the Orochi's use it.
How? Why? What?
The explanation is simple really: Orochi power is not flame power but all over increase in ki level to insane amounts. This argument helps to point out how Yamazaki and Leona's super human capabilities and brute strength (Leona could chop a tree down at the age of 8!). All the Orochi's have been shown to perform acts of inhuman strength on more than one occasion. Be it super speed (Chris) or brute strength (Yashiro). Heck even Shermie is strong enough to toss people several feet away despite formal training.
For Iori and the Yasakani's their ki was their flames. Hence their flames got a boost too in terms of fire power and intensity. Since Iori's powers are his flames, his flames wind up becoming godly in terms of strength as was the promise of the blood pact: godly powers. Does that mean that Iori can wield his family's original red flames with equal strength? Yes of course, he can. That is why he raped Goenitz without becoming weakened. Like I said, the purple flames aren't his strength but the Orochi blood in his veins. Otherwise Aoi's flames would be as strong as Iori's but they weren't. why? Because she didn't have Orochi blood.
from my manly site: http://www.freewebs.com/thedemon23/theories.htm
~Sado