Ito was hunched over on the bed while Yuki tried to calm him down. After hearing about what happened to Seireitei while he was absent, he was naturally shaken.
"It's that asshole's Kenzo's fault! I heard him scheming with Aikao about terrorising Soul Society the other day! He's even the one who kept Shido in a coma all this time! If I didn't get subdued that easily, then this never would've happened!"
He felt grief at his own weakness. If he was able to in form a Soul Reaper before the attack, then Shido wouldn't've had to suffer, and nobody would've died. Everyone was suffering now because of him. However there was someone who needed to hear this news more important than anyone,
"I need to tell Kai and Shinten about this!"
He quickly got up, but Yuki bluntly informed him.
"Shinten is dead."
Ito suddenly froze. He slowly turned around to look at Yukiko. A heavy shadow covered his face, leaving only his eyes visible. Red veins began to stand out from them, showing his visible rage.
Even Yukiko found it disturbing.
-Department of Research and development(underground)
Kai remained battling against Izuru in a battle of pure Zanjutsu. Although it was tough, Kai seemingly had an advantage and was even slightly winning with the use of both his swords, and the boost from Jigoku.
"This kid, where did he get that power from? Is it an ability from his Zanpakutō? But he didn't release it yet?"
Kai threw his Wakizashi at Izuru, who quickly deflected it with his blade, but then Kai flash stepped in front of him and pierced him in the right shoulder with his remaining Zanpakutō.
Mayuri, Hisagi and Rose watched the spectacle in an observation room hidden behind invisible glass.
Hisagi was a little shocked at how much stronger Kai had become. He was much stronger than when he was in the academy, but something had changed about him too since they first met. He was much more, serious.
"Hey, isn't this getting a bit too violent now? If this goes on any longer they'll both get hurt?"
Mayuri just lazily waved his hand at him, signalling him to back off.
"If your so upset then just leave. I'm looking for something else in this battle, not just information. In fact, what are you even doing here? Rōjūrō is here because Kira is his Lieutenant, but you?"
"I'm the reason Kai is here in the first place! I'm responsible for him! If you aren't going to continue with the questioning like asked, then I'll take him off your hands right now!"
Originally Rōjūrō(Rose), was tasked with questioning Kai personally, but Mayuri offered to do it privately, with him present instead. As Roses' Lieutenant, Kira got dragged into this, but Hisagi just slipped in on the way while watching Kai.
Hisagi's argument was undesirable, but even Mayuri could realise that this was going nowhere. He tapped a button on his desk, which turned on the microphone.
"Kai Kureno, I'll ask the next question. On the day of the attack, it was reported that you and Yuki Tsubokoniri left the protected Colosseum, but later you had returned with the hollow Leader Hollow chasing after you. Where did you go?"
Kai pulled out his Zanpakutō, while also catching his Wakizashi and quickly jumping away from Kira.
"I went to chase revenge. I sensed the Spiritual Pressure of the person whom I thought killed me, so I went to go confront her in the underground prison. I don't know what she was doing there, but I did get help from a Quincy who showed up."
His Alibi lined up with Albrecht's as well as the report that Nanao had written. If it was the same Fullbringer who made contact with Aizen, then this girl was the same person who Yuki said killed Kai in her report. Based on his answer, there was one more detail that needed to be found.
"You say that it was the person who you thought killed you? How did you find out it wasn't them? And who really did it?"
"Sakugo told me it was some guy named Tachibana. He's the guy behind that whole attack! He killed Grandmaster Yamada!"
Why would Tachibana kill what was supposed to be an ordinary human in the world of the living? Unless he knew Kai was special somehow, and had him killed so he could get involved in his future plan. This interview was finally getting somewhere.
"Hey. Did you know? Every spiritual pressure has a unique frequency. Even if you have the same amount of spiritual pressure as someone else, they have a distinguishable frequency. it's how we can tell different people apart when we sense them, and it becomes more prevalent between different races. What's really unique though, is that the frequency between a Shinigami and their Zanpakutō are the exact same."
Kai then shouted,
"You think I don't know that already?? I learned that in the academy!?"
Mayuri ignored his shouting and then continued.
"This is because a Zanpakutō spirit originates from the Soul Reapers Soul and essence. This rule is only true for your Katana style Zanpakutō. So tell me, when you used that strange power that comes from your Wakizashi, which turned some of your Shihakushō red, why is it's frequency completely different? Or in simpler words, where did you obtain a
Hisagi was a little shaken by this. The only Shinken he knew of, was Enrakyoten of the Tsunayashiro family, which had now been destroyed. If Kai had a Zanpakutō like that, then it would explain his immense growth.
"A Shinken? What are you blabbering about?"
Kai himself had not been aware of what he was holding, but Mayuri gladly decide to fill him in.
Something wasn't right. Kai could visibly remember the two broken halves of his Asauchi transforming into two separate Zanpakutō's. It happened the same day Linny died of course, it was still fresh in his memory. It didn't make sense for his Zanpakutō to be a Shinken, but at the same time, it would explain the irreparable damage done to Kai's soul.
The Jigoku Shihakushō would force the frequency of it's users spiritual pressure to change, allowing it fit and synchronise, at the cost of damage to the users Reiryoku which wasn't made to fit with it. Damage would accumulate over time, and eventually the spiritual pressure of the wielder and their Reiryoku would grow so differently, that their body wouldn't accept their own power, and lead to inevitable death.
"I don't know." Kai said. "My Zanpakutō has always been like that, that's just the way it is!"
Mayuri wasn't satisfied with that answer.
"Kira, increase the difficulty. Proceed how you see fit."
Kira took a new fighting stance, accounting for the injury in his right shoulder. The way he positioned himself, didn't fit his weapon however. Kai was confused to what he was doing, but then he realised he was about to release his Shikai.
"Raise your head, Wabisuke."