Ōetsu Nimaiya the God of the Sword
Ōetsu is nearly at least 5,000+ years old with all information within the Can't Fear Your Own World novel pointing towards this. Which in fact I whole heartedly believe due to the simple fact, Ōetsu had already seemingly established the Zanpakutō / Asauchi prior to saving a younger Yammamoto. Which either meant Ōetsu was a young adult ( as a soul mind you ) or he's simply been existing that much longer before Yammamoto was born.
Zanpakutō / Asauchi seem to be a finished product which still seemingly pre-dates the Gotei 13 by a considerable amount of time. Until at least the Gotei 13 is formed which by this point the Royal Guard was long standing. Whether it was it's own living embodiment prior to the formation, or if when the Gotei 13 was founded it was added as ' Squad Zero ' . The idea of Zanpakutō / Asauchi was at least 2,000 years in the making. The original version were far more destructive in the times of a majority of Japan being spiritually more aware. Within customs and the way of life, when wielded by anyone with a keen aptitude with spiritual powers. They could lightly manipulate the spiritual energy all around the. The wind to cut things? Literal lightning? This is my way of saying that some Japanese Mythology were literal mortals and or souls with high spiritual control. ( This is one aspect of Ōetsu's canon which in turn becomes my own canon across the board between all of my characters )
Ōetsu like a majority of the current make-up of the Gotei 13 was one that was simply born. With the exception that he has no parents. That he appeared within the Rukongai one day, and eventually is taken in by Ichibē. The Monk was the one who taught Ōetsu most of what he could know, but only because the rest came with experiencing life for yourself. It's his key importance within his upbringing as to why he joins ' Squad Zero '. To his becoming a Soul Reaper at a level no one could ever truly start at.
Ōetsu is the first person to ever master both the Shikai and the Bankai. While Ichibē is the first Shinigami to master them.
The Squad Zero are disturbingly mind shattering powerful to the point that they could destabilize the worlds. To this extent the Royal Squad are effectively immortal ( of course this doesn't need to be acknowledged by me of course ) being fitted with a literal essence of the Soul King. In which they live within at least decent proximity of him. Their immortality is all but assured even within the Royal Palace ( but it isn't assured at a set time with it being possibly minutes, hours, days? being completely mutilated certainly will take days ) even outside the Royal Palace. In canon it's tied to their names being used. Or it was tied to the Mad Monk? (Note: This doesn't mean any of you need to acknowledge this is as it essentially means. That my interpretation of Ōetsu is essentially on god mode. Which is partially true but he can still feel physical pain, emotional pain, and every other pain that can cripple a normal man! )
Ōetsu believes that their is one person that can change his mind on the bonds between, Soul Reaper and Zanpakuto, but he has a lot to learning to do first. That person is none other then: Ichigo Kurosaki. It's a biased one as they're are other could be better examples of a proper bond between their user and themselves. Except it doesn't matter as view of the entirety of the Gotei 13 is mixed at best. My own standing with my Ichigo and Ōetsu is shared only due to the relevance of my own headcanons. The relationship and ideals he sees carried in Ichigo will be primarily explored with other writers.
Ōetsu may or may not have taught or influenced the famous sword smiths of Japan. It's a rumor that he have been Yasuke. Neither anyone within the Royal Squad will conform, nor will Ōetsu, and that's because the God of the Sword hardly talks about his personal past.
Their is a living connection between every Zanpakutō it's not like the one normally shared between a shinigami and their spiritual partner. It's a higher bond. There is a feeling within his very existence when he is near one: he can tell when they are sad, angry, grief stricken, or are being neglected. It's almost as if they are talking to him. (Note: In development as to what else he might be able to understand from them. Whether he knows which one or whose along with anything else. )
Ōetsu was likely the second official member brought to the Soul Palace. Due to the significance of his invention and when it most likely had occurred from my breakdown of the timeline.
As a member of the Royal Squad ( or Squad Zero ) his power outside them is still formidable on par with the combined strength of the Gotei 13. It's only when it's un-sealed that it exceeds anyones perception. Ōetsu has been known to not utilize his raw power in the start of a fight and instead using his raw skill to toy with his enemy or try to reason with the enemy.
Note: These are my own personal headcanons so this goes without saying. Do not steal any of the writings here upon this page!
