Shin Sozoku

Shin Sozoku (心相續, Shin Sōzoku; literally "Soul Stream Continuance") is, in the words of Kurama, the highest of technique. It is, as of now, the only technique belonging to the Tenth Dan within the Haki Development System. It is the power to connect with all living beings, to harness the interconnecting musuhi that ties all people together, and in effect, becoming what Kurama refers to as "God" (神, Kami).

Overview
All systems of belief have a notion of what the existence of "God" (神, Kami). But for Kurama, who spits upon the idea of religion and beliefs, such things are ludicrous. Even so, he claims to believe that there is such a thing as God in this world, but it is not some omnipotent being that stands high above all others. God is, in effect, a creation of mankind. For people, who at their deepest core, wish to be connected and believe that there is something greater than just themselves, God is the system they named as such. God is nothing more than the force that connects all living beings together, that power that gives willpower the effect it has over one's self and over others. This is where all emotions arise, all relationships, all connections, and all thoughts. Loving one another, hating one another, to lose oneself, and to never give up; these are all aspects born from will. They are connections created when two or more wills interact with one another. After all, could love, hatred, happiness, sadness, ever truly exist if one was all alone in this world? Such a state is called nihilism, the rejection of interconnection.

Haki is no different than the usual things humans do and sense. Intimidation, fighting spirit, warmth of love, chill of hatred and fear; Haki is the ability to weaponize these emotions, these aspects of life that connect us together. It is for this reason that Haki is the only natural way to fight a user. A strike filled with Haki forces one that has gone astray with a devil's power to once more return to the realm of humanity, and accept the blow from another human. Haki weaponizes the connection between all living beings, allowing one to bypass a Devil Fruit's abilities altogether. Therefore, if this is true, the highest Haki technique would be one that grants complete access to the interconnection of all living beings.

Shin Sozoku, therefore, is a technique that turns the user into this idea of God that Kurama claims. All living beings, near and far, past and future, are all connected together by this living force that has existed for as long as life itself has existed. By becoming the embodiment of this absolute interconnection, one can tap into the will of any living being without fail. The user can strip away, from those before them, of the will to oppose them; essentially shattering their spirit to fight against the Shin Sozoku user. But there is good to this technique as well. In the same way it can rip away the spirit to resist, it can boost the morale of others as well, filling a soul with strength of will when all hope has vanished. Though this is just the tip of the iceberg. As it connects all living beings together, even those that have passed away, the user can become a medium for long-deceased souls, bringing them back to this world through them. One can strengthen others by passing on ancient life forces to them, even granting them powers and wisdom long thought gone. Bringing others back to this life, if only for mere transient moments, providing them with a physical form through and granting them a thought process through. There is ideally no limit to what Shin Sozoku can do, proportional only to the user's own spirit and capabilities.

A power such as this can be said to surpass even ; though Kurama states possessing the conqueror's Haki is not absolutely necessary for obtaining Shin Sozoku, it makes the process that much simpler, even if by a small amount. After all, in the end, what is a King to a God? Even so, for the normal individual, developing Shin Sozoku would be impossible in their lifetime, with Kurama attributing his acquirement of the technique to the unusual circumstances behind his Haki absorption and possession abilities.

According to Kurama, even he has not mastered this technique. He has stated it is unlikely for a human to ever be capable of truly mastering this technique, even for one with circumstances as unusual as his own, and even in his case, the scope of its influence, while vast, still pales in comparison to what Shin Sozoku can truly do. Kurama has said perfection of this technique will be vital for his goal of unifying the world under his command, but that it poses an ethical concern: for one such as him, that greatly values the human spirit, to reject free will so as to impose order, would be against his very nature. But to let humans continue as they are, as pathetic and foolish as they are, would be equally disastrous. Even so, Kurama's use of the technique permits him only a couple of minutes, in exchange for his ability to use Haki for an entire day, making it something he will utilize only in the most dire of situations. If he uses it in minute solitary bursts, he can extend his uses of the technique in a single sitting, but only by a couple more times.

Behind the Scenes
According to the Digital Dictionary of Buddhism, xīn xiāngxù (shin sōzoku in Japanese) means "continuance of the mental stream". It is a term that is associated with the concept of rebirth and reincarnation. While the parallel was unintentional, the reader can consider this concept to be loosely similar to that of the Madness of Order ability in the anime and manga series, Soul Eater.