Tsunade booted Itsuki out of the Medical wing, giving him scrolls filled with all the postmortem records of the last decade. He had to look for symptoms and catalog everyone that could have died due to Nx poison. It was quite a lot of work for him to do in a month but it was still infinitely better than painstakingly carving the medical seals required to perform apotheosis.
By the time he reached the orphanage, the sky was already dark. Making his way to his room, he tucked in sleeping Ichika and dismissed the shadow clone watching over her. There were two other clones sitting on the bed, one pouring over obscure fuinjutsu tomes that Itsuki secretly copied Konoha Library and the other performing complex arithmetic calculations regarding lightning transformation, the second element he was trying to master.
Sorting the memories of the clones, Itsuki frowned. Ichika was growing weaker faster than expected, she would need another Yang therapy soon. He was hoping to wait until completing Apotheosis, his Yang chakra would grow far more potent after that.
His chakra was imbalanced when it came to the yin and yang ratio, he had known that since he was four, and as he grew, this imbalance only increased. He was born with enormous reserves of Yin thanks to him keeping his knowledge and intellect from his last life and it became even more potent and increased exponentially as his intellect grew while his Yang half grew normally with his body. This imbalance should have normally killed him if he had not constantly channeled excess chakra to first Strength of Hundred seal and later into Yin and Yang seals on his palms.
Even now the chakra in the Yang seal was abysmally low, so much so that he had to ration it just for Ichika's treatment. But he used up almost all Yang chakra in creating C4 using the creation of all things.
Shaking his head, Itsuki unsealed the stacks of postmortem reports. Picking up the first one he started. When chakra became more potent than a limit, it starts to change body and mind in amazing ways. Like now, he no longer needs to sleep and feels no mental fatigue. Thanks to that, he could spend the whole night on his work.
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The next day Itsuki reached the Hyuga clan compound and took Hinata to the academy, without minding the glares of Hiashi or Neji or other Hyuga. Hinata looked positively happy at seeing Itsuki although she tried to not show it.
Itsuki shook his head, bemused, and led the Byakugan princess out of the Hyuga compound. Just as he reached the academy gate, he saw Jonin commander, Shikaku Nara also present at the gate along with Shikamaru.
Itsuki furrowed his brows at that. He never understood Shikaku's actions, especially the decisions that involved him. After border skirmishes, he let him and Kuhara go with just a superficial interrogation when his actions and ability to kill two jonins should have required at least a week in T&I department. He saved him from Danzo and Hiruzen's ploy, using his powers as a jonin commander to dismiss them of any suspicion.
But then he gave him the mission to be Hinata's bodyguard, a low-risk mission in the village in a time when war is on the horizon, Itsuki could not help but think Shikaku has some secret agenda regarding him.
Now seeing him seeing standing on the academy gate, Itsuki could not help but doubt Shikaku's motives. He was the one to personally assign the mission of escorting Hinata, he knows that Itsuki will be present here at this time. Today was just his second day as Hinata's escort.
Itsuki expanded his senses and sure enough, he was able to sense relatively strong chakra signatures hiding not far from there in addition to Anbu that guarded Naruto.
Shikaku took one look at Itsuki and turned to Shikamaru, "Go now, it is time for your classes." Shikamaru nodded hesitantly, picking up on the rising tension.
Itsuki too waved Hinata goodbye and turned to Shikaku, giving him a shallow bow, "Goo morning Commander."
Shikaku lazily waved his greeting off, but Itsuki was able to sense a maelstrom of negative emotions underneath the surface. Sense of loss, self-loathing, grief, and sorrow, so much sorrow that it startled Itsuki.
Without saying anything more, Shikaku went to his front pocket and pulled out a scroll before handing it to Itsuki.
Itsuki took it, and Shikaku gave a small mirthless smile, true emotions shining through his impressive facade.
Saying his piece, Shikaku vanished in a sunshin.
Itsuki looked at the scroll, feeling puzzled. He moved a little off way before opening the scroll. He just got one look at it but immediately shut it, his eyes in shock.
Taking to treeline, he hid far from any chakra signature before weaving an illusionary camouflage genjutsu around himself. Sensing that no one was around him, he finally calmed down and opened the scroll again.
At the start was a Nara Ichizoku, the Nara clan's symbol printed on the paper. Next to it was a write-in freshly dried ink, two words that shocked him so much.
"Kage Mane", the shadow bind technique. Itsuki read ahead and sure enough, the entire scroll contained in detail the shadow binding technique, the secret technique of Nara Clan.
Every clan has some secret techniques, techniques that can only be used by the members of the given clan. these techniques are guarded jealously and if any outsider gains access to them, the village is honor-bound to help the given clan kill any outside user. When First Hokage established the village this law formed the core of Clans law and has not been touched by any Hokage since.
Same way if an insider gives the secret technique to any outsider, it makes them a traitor.
Shikaku giving him Nara secret technique makes no sense, especially the fact he gave to him in a scroll. Secret techniques are passed verbally from one generation to another, and no written record of them is meant to exist for fear of theft.
"Why would he give me this...unless unless..." Itsuki's prodigious mind connected the dots.
'Mother never told me who was my father', Itsuki thought to himself, holding his head in his hands. 'Shikaku, if he is my father then his actions make sense...No, no, believing that at face value would be logical fallacy. It is entirely possible he had some long-lost brother of something, or some very older brother or something...'
Getting up from his position, he brought his emotions under control and rolled back the scroll without reading it till the end.
'Looks like I will have to visit Kurama Clan earlier than I wanted.'