Rangiku wasn't joking. As the lieutenant of the 10th Division, she really wasn't particularly skilled in kendo or Hakuda techniques, but she had quite a lot of experience in the development and application of Kidō and Zanpakutō.
In response to Rangiku's concern, Arata simply agreed, adding nothing more.
In the next few days, Arata spent his time eating, sleeping, and reading. He read the theoretical textbooks of the 4th Division borrowed from Isane and his own notes.
Since he was still injured and not suited for combat training, Arata didn't want to waste time, so he could only start from Kaidō.
Although in the original work there are very few descriptions of Kaidō techniques, it can even be said there are almost none.
Even the setting is mentioned only in passing, without strict numbering like Hadō and Bakudō. Throughout the story it's basically portrayed as a healing Kidō that emits green spiritual pressure light.
Alright, it feels just like watching a medical ninja on the side.
But the medical ninjutsu on the side at least has names, such as Palm Ninjutsu, Thin Disease Extraction Technique, and so on.
Here Kaidō doesn't even have names, and it often depends on healing Zanpakutō to carry the scene.
Arata initially also thought Kaidō was just something simple and perfunctory, but as he slowly studied these textbooks and notes, he realized it was just another blank left by the great poet Kubo.
Perhaps because the teaching materials Isane gave him were more oriented toward the general foundation and didn't mention too many high‑ranking Kaidō techniques, but on the basic and general level they laid out an extremely complete model.
Including the questions Isane raised during Kaidō class in the training course, such as the direction of rotation and flow of spiritual pressure and the division of spiritual pressure among multiple people, were actually written in the textbook as techniques.
Arata could be sure that the foundational accumulation in Kaidō and the potential for its development were definitely worthy of attention.
In short, during these few days, new ideas and new techniques occasionally came to him; after several simple simulations to confirm there were no problems, he used himself as the treatment subject.
Under normal circumstances, if Unohana Retsu or Isane Kotetsu knew about this sort of behavior, they would definitely scold him harshly.
How can a new method be used on people immediately? It must at least go through several rounds of experiments on mice before moving on to humans.
But what they didn't know was that Arata's talent for Kaidō was far beyond their imagination.
In other words, after possessing the Spirit King's bloodline, he learned very quickly and did not encounter bottlenecks at least for now.
The only thing he wasn't good at was likely the use of his Zanpakutō, and that was also related to Meigetsu's particular personality.
After all, generally speaking, Zanpakutō do not quarrel with their masters. They only want their masters to become stronger and quickly master their full power.
Furthermore, Arata's healing effect was very good. A wound that normally would need a week to heal had returned to its original state in just three days.
Arata felt that his body was now capable of normal and high‑intensity combat training.
Next, to take a closer look at the abilities Meigetsu left in his mind.
He rolled over and jumped off the bed, picked up his Zanpakutō, and headed to the family's underground training ground.
"Destroy everything to the end, Meigetsu!"
Arata held his Zanpakutō and recited Meigetsu's release words.
A powerful spiritual pressure surged from his body up to the heavens, purple‑black flames fiercely danced along the blade, and a cold and intoxicating aura continued spreading outward.
"Not bad, not bad. You recovered so quickly. Looks like that little white cat healed you well."
After successfully releasing the power, a slightly proud and cold female voice rose from his mind.
Arata was stunned. He looked around but didn't see Meigetsu. Was she simply communicating with him in the form of consciousness or soul?
"That's right, Master, you're not stupid."
"Although, having a sharp tongue isn't a good habit at least not for a beautiful and magnanimous lady like you, Meigetsu." Arata smiled softly and repeated the winning lines for handling tsundere girls from his previous life.
As he said that, he felt as if a current passed through the Zanpakutō in his hand, making it tremble slightly.
"Hmph… I wouldn't be happy even if you said so."
Although her words were still quite sharp, Arata could hear a trace of joy in them.
She looked like a tall and mature lady, but inside she seemed like a child who hadn't grown up.
"To make it clear now: I won't materialize again. You'll have to learn all the skills and abilities on your own, my Master," Meigetsu added.
At this moment she communicated with Arata only because he activated his spiritual pressure and performed Shikai.
Before a Shinigami grows to the point of being able to learn Bankai and master the true name of their Zanpakutō, materializing the Zanpakutō itself is actually a very energy‑consuming act.
Unless absolutely necessary, people usually don't do such things.
The last time Dark Moon (Meigetsu) materialized was also due to the external force of Tenshintai's transformation.
"I know, Meigetsu, just watch me learn." Arata expressed his understanding. He was very confident in his talent.
As long as Meigetsu didn't interfere, it wouldn't be difficult to cultivate the power of the Zanpakutō.
After the conversation ended, the female voice in Arata's mind gradually quieted, but he could sense that she was still quietly watching him.
Arata carefully felt the power transmitted from the sword. Although he sensed a slight restlessness, it wasn't out of control.
He tried slowly guiding and controlling that power, using more refined techniques of manipulating spiritual particles so that the spiritual pressure in his body interacted with the spiritual pressure on his Zanpakutō.
From simple to complex, from slow to fast, from clumsy to skillful.
If the cold, intoxicating aura of Meigetsu was an indiscriminate attack when first released, then now Arata could already make that aura target only enemies.
He himself, or those he considered friends, would not be harmed by that aura.
Under Arata's further control, the purple flames on the blade sometimes surged like waves, sometimes calmed like still water, and gradually became as easy to handle as his own hand.
He didn't start by practicing the powerful Dark Flame Slash or Soul Shadow Flash that Meigetsu had used earlier but focused on a more basic and essential control of the power.
He mobilized his spiritual pressure, and a tiny strand of purple flame leaped and wrapped itself around the fingertips of his left hand, but it didn't cause him any harm.
He gathered his thoughts and attempted to compress and reshape the flame.
The flame looked weak but changed flexibly and freely in Arata's hands, growing stronger as more spiritual pressure was infused, emitting a pressure that faintly distorted space.
Suddenly, the blade trembled slightly, as if responding to his thoughts and concentration.
Arata's heart tightened, and the purple flame on Meigetsu's blade entirely extinguished, then ignited again on his body but Arata felt no pain or discomfort.
It was more like the comfort of soaking in a hot spring.
An invisible connection was instantly established between Meigetsu and his consciousness.
Arata was slightly surprised and clearly felt it.
This purple flame… seemed to have a natural "lust" and "lock‑on" toward souls?
Like some biological instinct.