This is an extra chapter. This chapter has a lot of spoilers since its focus is on Isshin. Posting this one was a real dilemma for me. I wasn't sure if I wanted to share the true plans of Urahara or not. But, I think it's okay since Ichigo and co. will still have no clue about their true enemies.

With that said, I would love to hear feedback. Do chapters like this kill suspense/plot twists? Or does it not matter since most of us (?) have read the entire series?

"Ah, Shiba-dono. Come to check in on your son?"

Isshin smiled at the burly man standing in the doorway of Urahara Shoten. "Tessai-san. How many times do I have to tell you to call me 'Isshin?' I'm practically an exile from the Shiba clan," Isshin stepped into the shop as Tessai stepped to the side to lead him inside.

"You know that's not true, Shiba-dono. The clan would never strip you of your title."

Isshin smiled good-naturedly at Tessai before the latter opened the latch leading to the basement of Urahara Shoten. Isshin couldn't help but marvel at the training grounds every time he entered it. Given the resources of an exile, it was truly impressive what the genius Urahara Kisuke was capable of. Isshin smirked. I guess that's why he's called a genius.

Isshin watched Kisuke attack Ichigo with ferocity and tenacity that he wouldn't have expected him to use on a novice. "He truly is merciless, isn't he?" Isshin commented to Tessai, who had returned from upstairs with a cup of tea for Isshin.

"Would you have it any other way, Shiba-dono?" He handed the cup to Isshin who accepted it graciously.

Isshin laughed aloud. "No. The boy has been living with me for all these years. Pushing him a little bit won't kill him." His expression turned into a more grave and serious one. "Especially with what's coming." His gaze flitted over to Rukia, clad in Karakura's high school uniform. She was crossing her arms and chastising Ichigo from across the training grounds. Isshin watched as his son barked back at her before launching himself back into battle with Kisuke.

With a deep sigh, Isshin asked, "How are we on time?"

"The gigai that Kuchiki-dono is using is steadily sapping away her spiritual pressure. It is only a matter of time before the Hogyoku can finally disappear forever before the traitor can get his hands on it."

Isshin nodded. He just wanted this entire affair to end. Every misfortune that happened in his life seemed to be orchestrated by that man. Though in some ways, they were blessings. Had it not been for Aizen sending that accursed hollow, he never would have met Masaki. Isshin detested Aizen's existence. The man played with people's lives, without a care in the world. Isshin looked up at the faux sky of the training ground. He began to recount the conversation that he had with Urahara after Masaki's death.

"Kurosaki-san. I'm sorry for your loss." Standing at the threshold of Kurosaki Clinic were Urahara Kisuke and Ishida Ryuuken.

Isshin regarded the pair with the same dead stare that he had worn ever since he lost Masaki. He replied hollowly with a broken smile that he could barely muster. "Thank you." Isshin was never sure what he was supposed to say to people who offered their condolences.

Since losing Masaki, Isshin felt nothing but numbness and confusion. Why didn't Masaki use her blut? A hollow of that level should have been easy for her to take care of. There shouldn't have been any danger. There shouldn't have been any problem.

And yet, she was dead.

Isshin couldn't understand or wrap his head around the concept. Still, he would try to remain strong, for the sake of his children.

As if Kisuke could read Isshin's mind, he spoke up, "I'm sure you have a lot of questions. If you will lend me your ear, I believe I can provide you with answers from what I know."

Isshin looked at Kisuke fully, with a spark of life in his eyes. For the past week, he had thirsted for answers to explain his wife's death. He wanted to believe that by finding the answers, he could somehow fill the emptiness that her death had left behind. Wordlessly, Isshin led them into his home, inviting them to take a seat in the living room. The two visitors took his offer and sat upon the couch.

Taking it as a cue to continue, Kisuke cleared his throat. But, before he could speak, Ryuuken cut in, "Shiba, have you ever heard of the legend of The Sealed King?"

Isshin's eyes widened. "Are you telling me…"

Urahara nodded, "Unfortunately, yes, Kurosaki-san. It's true. Auswahlen has been enacted," Urahara paused and looked at Ryuuken who had a solemn expression.

"Kanae has been affected too," Ryuuken's fists clenched. Isshin looked at Ryuuken, feeling empathetic toward the white-haired man. "Her illness—"

Isshin placed a hand on Ryuuken's shoulder, signaling that he needn't continue. He understood where he was going. He clenched his teeth and took in a shaky breath. "But… Masaki is—" Isshin swallowed deeply, "—was echt. Why would—"

Urahara shook his head. "Have you forgotten your first encounter with your wife?"

Isshin's blood chilled. "Then… that hollow… from that time?" Kisuke nodded somberly.

Isshin roared as he punched the wall, leaving a hole in the dry wall. He felt hot tears stream down his cheek. "That damn hollow…" Isshin could feel the rage boiling within his soul. He wanted to rip the ones responsible for his wife's death to shreds. That black hollow from all those years ago. The Sealed King bastard. He would burn them with the hellfire of his Engetsu. Isshin had never felt so frustrated at the loss of his Shinigami powers.

Kisuke placed a hand on Isshin's shoulder. "I'm sorry, Kurosaki-san. But that actually brings me to my other reason for coming here." Kisuke cleared his throat, "All those years ago, I hadn't actually told you everything I knew, or rather, I hadn't told you my suspicions, about that hollow."

Isshin leaned forward, fully attentive.

"I told you that I had seen hollowfication before, that the process was intended to strengthen Shinigami by pushing past the boundaries of souls," Urahara closed his eyes and took a deep breath. "But, I hadn't told you that there was a perpetrator behind these heinous experiments."

Isshin couldn't believe it. He clenched his fists, and he glanced towards Ryuuken, who was wearing a similar expression of anger and astonishment. Masaki was an important person to the both of them after all.

"That man's name is Aizen Sousuke. For nearly a century, he has been conducting these hollowfication experiments upon Shinigami against their will. When his crimes were brought to light, he framed me, resulting in my banishment from Soul Society. I believe that the hollow that attacked you and Masaki all those years ago was yet another one of his experiments."

Ryuuken stood up from his seat on the couch, facing Urahara. It seemed that this was Ryuuken's first time hearing this story. "And where is this Aizen now?"

With a tired expression, Urahara looked up at Ryuuken, "In Soul Society. After all, he is the 5th squad captain of the Gotei 13."

Isshin could feel his mind reeling with this information. Aizen was a traitor? And for a century? He had never roused or created suspicion. He couldn't believe it. "Why are you telling us this now?" Isshin asked Urahara directly.

"Because I think your son is his next target."

If Isshin were still a Shinigami, the room would probably have burst into flames. "Explain." Isshin commanded Urahara with a menacing tone.

Urahara took a deep breath. "When your children were born, it was easy to determine what type of souls your twin daughters were. However, your son's soul is… complicated. By all accounts, your son's soul composition shouldn't exist. My fear is that your son may be exactly what Aizen has been hoping to achieve for the past century: a soul that has succeeded in breaking the boundary between Shinigami and Hollow." Urahara shook his head, "But, at the same time, his soul is completely contradictory to expectation. At this point in time, I cannot comprehend it."

The two men listening to Urahara shifted slightly, trying to absorb the words.

"With Masaki's passing, the tether between your souls has been broken. A portion of your Shinigami powers should theoretically be returning to you. However, at the same time, the hollow's influence that had possessed her, which I suspect now inhabits your son, will begin to awaken. And I'm afraid that if Aizen hasn't discovered your son's existence already, he definitely will now. And if Aizen achieves his goal, the balance of souls will be changed, resulting in calamity."

The tension within the room thickened. Ryuuken was the one to speak up first, "Then, what do we do?"

Isshin clicked his tongue. "We stop him."

Ryuuken shot an irritated look, "How, Shiba?"

"Not to worry, gentlemen. I have had nearly a century to give this some thought after all," Urahara wasn't smirking, but his voice betrayed a hint of smugness, so he might as well have been. "Kurosaki-san, I'm sure you remember the hogyoku I used in order to stabilize your wife and tether your souls. Aizen has been using his own hogyoku to conduct these experiments. However, Aizen's hollowfication process has been unsuccessful because his hogyoku is incomplete."

Isshin folded his arms together. He was beginning to follow where Urahara was going. "So, as long as his hogyoku is incomplete, Aizen can be stopped."

Urahara grinned, "Precisely. Aizen has been seeking my hogyoku for decades. But, it is in a dormant state, and at Aizen's current state, it cannot be used or found. Which is why, I am developing a method to destroy it, once and for all."

Isshin nodded. "How long will it take?"

Urahara heaved a sigh, "Several years. I will also need to find a suitable soul to insert the hogyoku."

Ryuuken's brows furrowed, "Your brilliant plan is contingent upon finding a soul to insert this abominable stone?"

"Now, now, Ishida-san, I would think you would know me better than that. Until Aizen can complete his hogyoku, he cannot strengthen himself beyond the limits of a Shinigami, now can he?" Urahara paused, flitting his gaze between the two men. "Which is why, I believe, Kurosaki-san, your son is our ace."

"What?" Isshin bellowed. "Ichigo is a 9-year-old child. You can't expect him to go up against someone like Aizen!"

"Of course, not now, Kurosaki-san. If my theory proves true, your son, the boundary breaker, is the only one who could stand against Aizen! We could develop his abilities—"

"Absolutely not! How could you even suggest such a thing? Just look at what has happened at his first exposure to Hollows! My wife is dead! And you want to develop that—"

"Would you rather he fall into Aizen's hands?" Urahara shot back calmly, leaving Isshin tongue-tied.

A picture frame caught Isshin's eye. He picked it up and held it in his hands. It was Ichigo, grinning ear to ear from the first day of his karate class. Such an innocent and blissful expression. Isshin never wanted such a destiny for his son. While he wished that he could've had his Shinigami powers to protect Masaki, he also wished that he had never had them to begin with. He wished that this world didn't have Hollows, Shinigami, or Quincy. He just wanted his children to live uncomplicated, human lives.

But, that wasn't their fate.

Isshin heaved a deep sigh, steadying himself and restraining tears. "Fine. When his powers awaken, I'll leave it to you, Urahara-san."

Isshin watched the pair bicker with each other. The way they got under each other's skin made Isshin wish even more for a different fate for the two of them. When Urahara had told him that Rukia was the suitable soul to destroy the hogyoku, he was elated. But then Urahara had explained that Rukia would slowly turn into a human, saving the realms at the cost of Rukia's powers.

It made Isshin sick to think about it. Isshin had lost his powers for Masaki's sake all those years ago, but he had done it by choice. Forcing this fate upon another person felt wrong and awful. But, it was for the greater good. He hoped that Rukia would understand.

He heaved a deep sigh. He could only hope that things would turn out as planned.

He would atone for the way he treated them when it was all over.

Hope you enjoyed reading this extra chapter! See you for the next one!