Thread:Silver-Haired Seireitou/@comment-5778280-20151022012026/@comment-2089817-20151031042911

From what I've come to understand from Kaidou, which has been used and explained most prominently by Unohana, I believe it operates like this.

First, I'll go into what I've based on conclusions upon.
 * When Unohana explained her method of healing to Ichigo, she said this: "By it's very nature, Kidou-based healing restores reiatsu first. Then, the restored reiatsu is combined with external reiatsu from the healer in order to systematically repair the body itself. In other words, if the body is already healed, restoring reiatsu is child's play."
 * Kaido is called "Turn Way", or by reading it as we would read Hado or Bakudo, "Way of Turning". Just to be sure on what we could read this as, I translated only the first kanji, 回, and got something like "counter for occurrences". So my guess is "turn" is meant to refer to the turning around of a situation.
 * Hachigen, who is arguably one of the greatest, if not the greatest, Kidou specialist showed in the series thus far, could use a form of advanced Kidou healing that was reminiscent of Orihime's rejection of phenomena. No, even greater, considering that he could repair something that even Orihime could not. He even goes as far as to call this form of Kidou healing as "Time-Space Regression".

My conclusion is that Kaido is capable of altering conditions. From what I believe, it coincides with something Nanja created a while back known as Henkodo, but I could be mistaken. Depending on the skill level, it can perform a multitude of feats. Standard Shinigami can use basic Kaidou. If Kaido is, as one of the translations suggests, a "counter for occurrences", it works by changing or altering something that has happened. When taken to the highest degree possible, it can even mimic Orihime's rejection of phenomena. Basic healers can only perform simple tasks, such as "countering" the loss of reiatsu from damage or a battle by restoring it back to full. Advanced users, like Hachigen for instance, can even go as far as to quite literally "counter" something that has already happened by literally reversing the spacetime in a particular situation; such as healing Tsubaki, who was completely destroyed, back to completion, a feat that Orihime, who actually possesses rejection of phenomena, was incapable of doing.

Generally speaking, Kaidou is magic focused on changing something that has already happened. Whereas Hadou is magic focused solely on destruction, and Bakudou is focused on restraining, Kaidou is focused upon change.

Could this be used to enhance physical fighting ability? Eh... It could be a stretch. But I think it could, yes. One way of looking at this is that one often is incapable of attaining their 100% potential strength because human error makes it impossible for any form of training we do to perfectly bring out every iota of our capabilities. We end up strengthening muscles unnecessary for combat, such as those who lift weights, while ignoring muscles that actually need to be strengthened. And so on. So... Kaidou perhaps can be used to completely undo the human error over the course of a person's lifetime of training so that their fullest potential strength can be unleashed. It would be like the ritual used by Elder Kai to bring out Gohan's latent potential; someone who was already an adult, so it's not like he was still growing by much body-wise.

To be honest with you, don't look too much at Kanshume. I am considering to delete it, since I made it before I ever really gave Kaido any thought and forged my theories around it. But anyways, I hope this helps.