Kaguya was having a normal day. She was sitting on her wheelchair outside enjoying nature at the local park.
The sun was shining and there was not a cloud in sight. The grass was a vibrant green and trees decorated her surroundings. It was a picturesque scene that was carefully maintained by the park workers as the city park itself was very big. It occupied almost a one by one mile perimeter, making it a popular location for runners and those walking their dogs.
Tenji was currently away buying food from a food truck for both of them. But Kaguya was happy to be in such peace, the stresses she had in the Otsutsuki clan felt so distant to her. And although she was unable to walk and even her bodies ability to use chakra damaged. A sudden unknown attack in the form of an explosion directed at her and Isshiki the moment the arrived at this world had.
That had completely interrupted her right before she tried to cut Isshiki down.
'It's been years since then'
'I have children'
Kaguya looked up with a slight warmth settling in her chest.
'I have Tenji'
"Kaguya Otsutsuki."
Mitsuo appeared from seamingly nowhere Kaguya who was absorbed in her thoughts was completely startled by his abrupt appearance.
"The land of Kagaku is under threat from Isshiki Otsutsuki I need you to tell me absolutely everything you can about the Otsutsuki Clan."
"..."
Kaguya was completely caught of guard by this assault on her past. She was at a local park with her husband nearby and now is the time for this?
"We can save this for later Riku Tensai. I have better things to do right now."
All Kaguya wanted was to spend her time with her family and peace. She wanted nothing to do with the distant machinations of war or her clan. She was happy, and she wanted nothing to encroach on her simple daily joy.
'Leave me alone'
"I'm afraid I can't do that Miss. I need everything you know right here right now."
'Get out of here'
"Your husband will not be showing up for at least 2 hours due to my arrangements."
'I want to see Tenji'
"If you answer my questions your children will no longer require weekly checkups."
"..."
"..."
"How can I trust you."
"I am the Riku Tensai I have the power to do as I please, so lying is not necessary."
"..."
"What do you want to know?"
~~~
Tenji was back in the inventory. He had obtained a treasure trove of information from his long interrogation of Kaguya.
Everything Mikitaka had said was correct but now he had much more context to that information and on the state that Isshiki must be in.
To summarize everything Mitsuo learned. The Otsutsuki clan were an interstellar parasite race. Their home planet had truly enormous vitality and in turn a species of world trees was born from that world that converted a little bit of that vitality into chakra fruits for no other reason than that for its seeds processed that raw chakra a bit easier than natural energy for growth. The Otsutsuki simply ate these fruits and eventually evolved their eyes as special organs that could process the massive amounts of chakra in their body into certain effects. Eventually their society simply advanced in their understanding and usage of chakra into becoming an interstellar race. Their home world was monopolized by their leaders leading to other Otsutsuki resorting to planting chakra trees on other planets, but most worlds simply do not have the sheer vitality of their original planet and die out for just a single tree.
As for Isshiki, he and Kaguya were nuked by the Inventory the moment they were detected. And these aren't normal nukes because they were designed by Mikitaka for his personal use. They probably had all sorts of exotic and stupendous things inside them that could harm even a peak state Otsutsuki like Isshiki. He was now in an extremely damaged and depleted state, but it was clearly not bad enough to call for reincarnating with a karma seal or possessing someone as the vague silhouette Mitsuo saw was horned.
Mitsuo had pieced all this together in a short time after interrogating Kaguya.
The reason that Mitsuo had rushed to interrogate Kaguya in the way he did despite the bad impression it would make was for a single urgent reason.
Mitsuo had found Isshiki. He was absolutely in a rush. He was going to mobilize every incomprehensible and terrifying weapon he had in the inventory. He didn't know how long he had until Isshiki would simply portal to another dimension or location, losing his location.
'But what if I lose...'
'Then Akira will take over.'
Mitsuo decided that if he were to lose his confrontation with Isshiki he would send all the information on the Otsutsuki and the entirety of the blueprints left behind by Mikitaka for the Land of Kagaku, publicly, on the infonet. He also had plans for Mikitaka's personality data, although Mikitaka told him to avoid using it because he didn't like it. Mitsuo felt like its practical value outweighed his consideration for his teacher if he died.
Elsewhere in the orbit of earth were gigantic space factories assembling and releasing space lasers into orbit. 10 space lasers were already constructed right now. Another one would take a week.
All of these space lasers arranged themselves into a formation at geocentric orbit so they could shoot at Isshiki at all directions from the sky at any time all at once. If they were in the atmosphere each one would be emitting extremely loud rumbling noises, every single one was primed to fire in an instant with enough output to rival the strongest nukes all concentrated into a single point. Of course this point would be a large area that would become completely eviscerated and erased.
'If Mikitaka was alive right now he would be much more enthusiastic.'
Mitsuo could almost see it. If Mikitaka were doing this instead of him he would be humming some kind of tune with a big smile on his face. He'd say something about trying out his new innovations and say how everything that was happening is cool and amazing.
But Mitsuo was much more burdened than his free spirited teacher. The legacy of science and advancing civilization lay on Mitsuo's back. 200 years of building bit by bit without his teacher, relying on the blueprints he had left behind and branching out further. He remembered returning to his younger days of spending late nights many times just to fully understand and recreate a single component of something Mikitaka could've taught him to make in a day.
He would not let invading aliens mock those precious things.