Yamata no Orochi
(Also known as Hachimata)
Tale in the Legend of the Tailed Beasts: Yamata no Orochi is a Snake bijuu. It has crimsom red eyes, eight heads and eight tails (also depicted to having trees and vines growing around them) and has the power of the Demon world, a symbol of evil. Each head of Yamata no Orochi represents a symbol: Soul, Ghost, Evil, Devil, Monstrous, Kill, The Afterworld and Death.
Its powers were originally weak, the members of the Kusanagi clan, when attacking it, acted carelessly, using the legendary sword Kusanagi no Tsurugi (Oro’s sword). Because of that, as a consequence, Yamata no Orochi takes the sword from them, absorbing the power contained inside, and becoming an incredibly powerful creature, and finally storing it in its body.
With the new power, Yamata no Orochi releases an insane amount of dark energy, awakening the other Bijuu and becoming arrogant. Yamata no Orochi proceeds to defeat many of the Bijuu, but when it battles with Kyuubi, it is defeated. The cause of this is simple: Kyuubi has an unlimited amount of power, making even a hole in the Kusanagi sword. As this happens, it shows how tremendously powerful Kyuubi is, deserving of the “King of Bijuu” title. Not even Sarutobi and Enma (I’m not sure how those two are into the legend) could scratch the Kusanagi no Tsurugi. (That makes connections to the Oro x Sandaime battle)
Legend also depicted it as having a power able to rival Kyuubi’s [in quality], but the fact is, Yamata no Orochi’s does have a limit.
Fate: Yamata no Orochi awaits a genius of the Yagami clan (:shock: Remplacez Yagami par Uchiha

), which is the arch enemy of the Kusanagi clan. The purpose is to awake it [Yamata no Orochi], in order to fight Kyuubi again.
Since Yamata no Orochi’s power inherits in the Yagami Clan, If the heir appears as the first genius in 1000 years that is able to awake Yamata no Orochi’s ability, it will be completely restored. Once the process is done, the genius with such crucial task will be destroyed due to the true body of Yamata no Orochi resurfacing, which has an all-new power. It won’t be found before the decisive battle with Kyuubi, and will be able to kill no matter of thing, destroy any type of place, and attain infinite vision (as Kyuubi has). The core of Yamata no Orochi’s power is in a kind of forbidden sealing jutsu. As soon as the Yagami clan heir comprehends enough of it, a bigger, much stronger power will surface in the grasp of Yamata no Orochi.
Japanese Myth Appearance: A super Snake of Eight heads and Eight tails, attached to a single body. Has a deep brown color. It definitely is the biggest bijuu - the lenghth of it is over eight mountains. Originally, it was weaker than Houkou and Nekomata; however, that was 1000 years before a brave warrior tried defeating it with the Kusanagi no Tsurugi. In the process, the sword’s power is absorbed instead by Yamata no Orochi, thus greatly expanding his power. He continues though to be able to use freely the sword in his belly.
Ability: The legendary sword: Kusanagi no Tsurugi; summoning of evil spirits
Kyuubi no Youko
(Nine-Tailed Demon Fox)
Jinchuuriki: Uzumaki Naruto
Tale in the Legend of the Tailed Beasts: This is a bijuu in the shape of a nine-tailed fox, and the strongest of them all. The reason he is so powerful is simple: Kyuubi has an unlimited amount of power, earning it the “King of Bijuu” title. The power is generated by Kyuubi’s Fire Seal, and as a result, after battling for 100 years with Yamata no Orochi, it becomes exhausted; but Kyuubi continues standing, able to fight. It is also pretty cunning and smart.
Fate: In unclear whereabouts, Kyuubi continues to kill all the people on his way to
find the one who awakened him, and
the one who managed to seal him before. (
Yondaime, surement) Yamata no Orochi didn’t tell Kyuubi, though, that
the one who awakened him was the Eight Tails himself.
Personal Notes: Interesting how he searches for the one who sealed him. Also, it would be nice if Oro was the cause of Kyuubi’s awakening – the reason Kyuubi attacked the village may very well be because it’s the place he was last seen.
More info about Kyuubi: The Kyuubi is an intelligent demon that is capable of speech and has a scathing, sadistic personality. However he has also a sense of fairness and sarcastic honour, as he sometimes helps Naruto when he is in a difficult situation. This could be for purely selfish reasons, however, for it is speculated that if Naruto dies, then the Kyuubi will die with him. It seems likely that the Kyubi has some concept of a loathing respect for Naruto and even more so for the Fourth Hokage.