Kaguya did want to meet with Hagoromo. Ever since she was released from her seal and learned that Hagoromo's spirit was still hounding the world, she wanted to tell him off.
Unfortunately for her, despite all her strength, she simply could not reach the plane of existence where he currently resided.
It wasn't a question of power. Kaguya had enough power to create basic dimensions at a whim.
It was a problem with access. She had no idea how to access that plane.
Some things... one simply can't just power through no matter how much energy he has at his disposal.
Of course, during one of their intimate moments when they were cuddling in a bed after an incredible night, she did inform Rei about this wish of hers and the problems she was facing.
Honestly, she thought he had already forgotten about that since he never brought it up again and Kaguya did not expect him to solve all her problems for her.
And yet, here she was. Sitting in the middle of a sealing formation spanning an entire room that should let her spiritual form access the plane of existence where Hagoromo's spirit was hiding and observing the world.
She finally could verbally spank that misbehaving boy of hers!
The seals flashed with chakra and Kaguya felt as if she blinked despite not doing so, and the world in front of her eyes shifted.
Looking around, Kaguya found herself in a depressing edgy room that was mostly empty. She was sitting opposite Hagoromo and when she saw his jaw on the floor and his eyes wide due to her sudden and unexpected arrival, Kaguya giggled into her palm.
But her eyes were not smiling at all...
...
Contrary to the popular belief, Hagoromo was not observing the Elemental Nations twenty-four-seven nor did he know everything that was going on. He was just a man, no God as the people liked to believe. And like any other man, he was not all-seeing. He had only one pair of eyes.
Yes, his eyes could see much further away than anyone else's, even going beyond the realm he was in right now, but he had his limit. He could observe only one place at a time and there were simply too many things going on at the same time in the world.
On top of that, not all of his time was spent staring at the Elemental Nations. Yes, he was bored out of his mind but even he needed a break from time to time. He liked to take week-long breaks to just... meditate and let his mind go blissfully blank.
No plots, no worries, no problems, just basking in the quietness of his mind.
If not for his inner peace, he would have gone mad a long, long time ago in this realm.
That said, as of late, the world was starting to near another breaking point, another crucible that would test if the world would be destroyed or not. Plots of those hiding in the dark were reaching their conclusion and Hagoromo could already tell there would be a war starting in just a few short years.
A war unlike anything seen before in the Elemental Nations.
Hagoromo could do nothing but watch, but he was at the very least fully capable of following the actions of Black Zetsu and the fake Madara. He watched them in worry, praying somebody would stop their madness.
Yet, it was obvious this calamity would not be stopped before it was unleashed onto the world. Just like any other before it.
Over the years, Hagoromo lost a lot of his initial faith in humanity. He watched the reincarnations of his sons fight over, and over, and... over again in an unceasing foolish battle that had no end goal. They fought and fought, usually for the stupidest of reasons, and more often than not, this led to the death of both of them, only feeding the circle of hatred.
Hagormo could withstand a lot but even he was getting tired, weary of it all.
And then, Madara and Hashirama came, uniting together to forge a better future.
Hagoromo was overjoyed at the reincarnation of his sons finally finding a way to reconnect, become friends, and work together towards a brighter future...
But his joy didn't last long and Madara fell to the ploys of the Black Zetsu, causing Hagoromo to grit his teeth at the damage his 'third brother' was causing in the world. If he had any idea that his blasted mother made another last vain attempt at freedom just before she was sealed, he would have turned every rock in the Elemental Nations to find his 'third brother' and permanently deal with him.
Alas... he had no idea and the result was the Elemental Nations being plunged into deep, centuries-long darkness.
The last attempt at the freedom of his mother pretty much screwed the generations of ninshu users to come, going so far as to corrupt his own two sons and goad Indra to both fight against Asura and create the abominable ninjutsu the people of nowadays used to kill each other.
And now, history was repeating and the board was set once more. this time, just with much higher stakes going on behind the scenes.
Two new reincarnations of his sons were born, both having their own circumstances. With the Rinnegan created by Madara, Black Zetsu and his pawns were preparing to start their ultimate plan, and the somewhat peaceful era was going to be interrupted the second the first bijuu was captured.
But that was not all...
Some time ago, Hagoromo did feel someone penetrate the realm he was trapped in and stare at him right through the boundary. The second it happened, Hagoromo stiffened like a deer being watched by a wolf, sweat drenching his back...
And then the feeling was suddenly gone as fast as it came.
Hagoromo scrambled to peek back, to find who was powerful enough to do that. His mind whirling in panic with numerous possibilities and all of them so dangerous to his beloved world that he felt afraid for it like only once before.
Yet, he couldn't find anyone. No, he... couldn't 'see' anyone. His senses were telling him there was someone but his eyes simply refused to reveal it.
Hagoromo's mind flashed to the time when his mother taught him how to use his eyes and how she could conceal herself on instinct purely because her Rinnegan was much, much more powerful than his own.
But he quickly shook that thought away. That was nigh impossible.
His mother was safely locked in the Moon.
There was no way for her to get free so of course, it had to be some other Otsutsuki. That was good. That meant his world still had a fighting chance. They could still gather their heroes and win.
As long as it was not his dear mother, the world was not yet done for.
Hagoromo knew best the level of power his mother held. Two people on his level could not put a scratch on the woman for months. And it was ever so painfully obvious she had no idea how to use her abilities to fight at the time.
But during their fight, she was slowly but surely getting better, grasping her abilities more and more, and that's why Hagoromo became desperate, opting to seal her away. For he knew if they fought for another week, neither he nor Hamura would be able to reach Kaguya anymore.
Hagoromo's worries only intensified when he felt the same kind of stare on him from time to time. It usually ceased as fast as it came, but sometimes, he was left squirming for a few minutes under the scrutinizing and slightly hostile gaze.
But no matter what he did, he couldn't find the culprit. And he did try almost everything he could.
Was it any surprise his no-longer-beating heart almost stilled all over again when Kaguya Otsutsuki of all people appeared in front of him?
'Not her, anyone but her!' Hagoromo repeated in his mind while his jaw dropped and his eyes widened in horror.
Yet, his mother only sweetly smiled at him... but her purple pupil-less eyes betrayed the arctic coldness of her heart and Hagoromo felt as if he was shrinking under her gaze.
The resentment she felt towards him was palpable in the air and the tension between them was only increasing by the second, making him inwardly freak out in panic...
When suddenly, it was as if a great burden was lifted from his shoulder, letting him take a deep breath.
But his new-found relaxation didn't last long as he realized Kaguya was not using any sort of technique or even her chakra to pressurize him. It was all simply her presence and...
'She learned how to control some of her power!?' Hagoromo looked at her, the horror in his eyes increasing. Abruptly, the spark in his eyes turned to apathy and... resignation. 'The world is doomed.'
There was simply nothing more he could do. The monster his mother was had won.
But instead of getting instantly slaughtered as he thought, Kaguya only smirked at him.
"Well, hello there, Hagoromo. How is watching your beloved humans slaughter each other treating you, my least favorite son?" She calmly drawled as she slowly looked around. "Seeing you trapped here by your lonesome self, unable to find eternal peace... I guess serves you right, you prick." She nodded to herself in satisfaction.