The two, Silas and Yoruichi, gathered in the secret training area. Built by Kisuke, its location was hidden beneath Sōkyoku Hill, a rocky mesa located in the center of the Seireitei. Inside, Silas scanned around. It looked hardly any different than the training room in Kisuke's shop. The only notable difference was that this one had a hot spring to heal injuries.

It was an interesting scheme to build it in the one area most Soul Reapers didn't visit, but it still had its flaws. For one, if a Soul Reaper was familiar with another Soul's spiritual pressure, they could locate whoever was inside.

Silas patiently waited for Yoruichi's return after she departed in order to grab the needed material to begin. Though she hadn't told him what she was getting, he already knew what it was. Or rather, he had familiarized himself with this moment in the story as if he had just read it yesterday.1

A Bankai generally takes ten or more years to learn. Kisuke, however, developed a method to learn it within three days. Using a special tool known as the "tenshintai" that belonged to the Stealth Force but was invented by Kisuke, it could forcibly materialize the spirit of a Zanpakutō when stabbed by its blade.

Once the spirit of the Zanpakutō became an external being, the user would have to force it into submission. Anyone could externalize their Zanpakutō's spirit, but it normally took years of training to do so. A tenshintai merely allowed someone to draw out a Zanpakutō's spirit into the world without that training.

However, there were some unanswered questions about this training method. Kisuke and Yoruichi stated that the training should last a minimum and a maximum of three days. This was disproven when Renji completed the training in less time. Then there was Kisuke's quote on how Ichigo's powers were far superior to his own if he were to undergo this training.

Silas more than met the qualifications to subdue Zangetsu. The real question lied in whether or not it would be the same method of battle that Ichigo underwent with the manifestation. If it was, Zangetsu would summon hundreds of swords, each representing a piece of Silas's heart. All Silas had to do was find the one sword that was forged for the sole purpose of combat. And since Silas's heart was unwavering, only one sword would be summoned anyway.

• • •

Yoruichi finally returned with the tenshintai. It looked exactly like he remembered: a white cardboard cutout in the shape of a man. A brief moment was spent clarifying on what he had to do.

"That's it for explanations," Yoruichi announced. "Three days is all you have. I'll use my powers to keep Zangetsu in its external state."

"There's no need to be in a rush," Silas claimed. Yoruichi became a tad irritated, stating that arrogancy would be his downfall. Silas, however, wasn't being arrogant; he truly believed he could achieve and perfect his Bankai in one day. But what he was truly after was learning techniques from Yoruichi!

"What gives you the impression that I can teach you anything other than Bankai?" she asked.

"You expect me to believe that a mere cat managed to bring a tenshintai all the way from the Stealth Force and back?" Silas retorted. He was implying that a feat like that was impossible for a cat her size.

"Well, I did…"

"No, you've been hiding your form."

Smiling, Yoruichi's body transfigured into a woman's. Her sleek black hair cascaded down her sun-kissed skin, revealing her eyes of mischief. It wasn't as purple as depicted in the television series. And although she was naked, Silas remained solemn. "Funny… I was expecting more of a reaction from a teenage boy," Yoruichi tried teasing.

A spare change of clothes was put on to hide her nakedness. Tying her hair into a ponytail, she asked what he wanted to learn. There were a lot of techniques to absorb from her arsenal. Yet only one of them was worth training above all else. So Silas asked her about the Stealth Force and her background. She briefly explained her role while leaving out unnecessary details.

Yoruichi had once been the captain of squad two over one hundred years ago. This particular squad's captain also leads the Stealth Force, one of the three main military branches within the Soul Society. They were under direct supervision of Central 46, being in charge of carrying out top-secret operations such as assassinations and the execution of other Soul Reapers who broke the law. Yoruichi, who had also been part of one of the four noble families, had become the first woman to ever hold the leadership position.

"Something about the Stealth Force doesn't make sense," Silas commented.

"And that is?"

What Silas was truly doing was using his words carefully to reveal Yoruichi's technique, shunkō. "There is one technique I know, but I refuse to teach it to you. Besides, it'll take far more than three days to learn."

"At least tell me what it is," Silas urged. There were a lot of things he remembered from Bleach, but shunkō wasn't one of them.

Yoruichi explained that it was the highest form of hand-to-hand combat in this world, using a combination of kidō and physical techniques. The kidō that engulfs the user's body is so dense that all manner of fabric on the back and shoulders rips apart upon activation. What she didn't know that Silas knew was that only two people had achieved it: Yoruichi herself and Soi Fon, her pupil, who managed to learn it without Yoruichi's guidance.

If Yoruichi wouldn't train her pupil, believing the technique was too dangerous, she had no thoughts of teaching it to Silas. But that hadn't mattered to him. All he needed was to understand that it could only be released by pressurizing an elemental-based kidō inside the body. Now that he knew that, he only needed enough time to actually practice it.

"Let's begin your Bankai training now," Yoruichi urged.

The moment Silas stabbed the tenshintai, Yoruichi began the linking process to connect a small amount of her spiritual powers to it. A crackling screech plagued the training grounds, forming a white and red light. The light faded, revealing Zangetsu in the place where the tenshintai had been. Zangetsu was on its knees, head down.

When Yoruichi sensed a Hollow's spiritual pressure emitting, she gasped. This was the first time she had ever seen Zangetsu. Despite knowing the name of Ichigo's Zanpakutō, she had never expected it to be a Hollow!

"It never ceases to amaze me how you know everything, Silas," Zangetsu said, standing up while showing off its sadistic smile.

"Silas?!" Yoruichi repeated.

"Do it…" On Silas's commands, Zangetsu summoned a lengthy blade, turned around, and slashed at Yoruichi!

1 What the author tots did.