Kaguya was just a member of the Branch Family before. If there was anything special about her, it was that she was stronger than the other Branch Family. Otherwise, she wouldn't have become Isshiki's servant.
It should be noted that Isshiki is far more powerful than most of the Main Family, and his vision is far from limited.
As a member of the Branch Family, Kaguya does not possess the Rinnegan of the Main Family, nor does she have any Kokugan; she only has a pair of highly pure Byakugan.
Perhaps that's why Isshiki chose her.
As Branch Family, Kaguya knew she had to unconditionally obey the orders of the Main Family. She had nothing else to offer but the Taijutsu of the Ōtsutsuki Clan and her ever-improving Byakugan.
Thus, through her efforts, the terrifying Taijutsu of the Eighty Gods Vacuum Attack was born.
Although it is the strongest Taijutsu, the Eighty Gods Vacuum Attack not only requires physical strength, but also all Chakra attributes.
It can only be said that Kaguya's talent is the same as Isshiki's, both being among the top tier. However, she belongs to the Branch Family, Isshiki belongs to the Main Family.
But after following the Isshiki, she realized she had walked down a dead end.
Planting the God Tree on Earth and harvesting its fruit was an order from the Main Family, but Isshiki did not return, which is the most terrifying thing.
With the addition of the Kokugan, his ambition had already swelled. Upon seeing the unique planet Earth, he knew that the God Tree Fruit on this planet would possess extraordinary and outrageous abilities.
So he changed his mind and decided to keep the fruit for himself, to claim the God Tree for himself, instead of taking the fruit back to his tribe and waiting for it to be distributed.
His goal was to become like Shibai Ōtsutsuki, because he had also developed the Kokugan and sensed that level of understanding.
Having learned of Isshiki's thoughts, Kaguya naturally wouldn't sit idly by and wait for her doom.
As Ōtsutsuki, even Branch Family can be resurrected infinitely, but the prerequisite is that they must first return to the clan. The resurrection of the Branch Family requires the clan's help, but Isshiki will not go back. Having monopolized the fruit and the God Tree, how could he dare to return?
In this way, only she will die.
Therefore, Kaguya could only endure it until the very end, when the day of sacrifice arrived, she launched Isshiki sneak attack.
Is the Isshiki strong? Yes, it is very strong!
At least, in a head-on confrontation, Kaguya was no match for her at the time, but she wasn't completely without a chance to fight back.
Therefore, Kaguya chose to launch a sneak attack and smashed Isshiki of Ichishiki's body.
And so, on the verge of death, Isshiki was sacrificed by Kaguya to the God Tree God Tree, becoming nourishment for it instead.
However, since Isshiki is from the Main Family, the ability of the wedge is difficult for the Branch Family, but for the Main Family, it is already second nature.
Even though he was on his last breath, Isshiki still found an opportunity to escape using his Kokugan. Later, he encountered the monk, carved a wedge, and possessed him.
As for Kaguya, she's already followed the wrong person and even attacked the Main Family. Going back means death, and surrendering also means death, so she might as well go all the way.
So she ate the fruit.
As God Tree that grew on Earth, the planet of life, both the tree itself and its fruit are far more powerful than any fruit ever received by the Ōtsutsuki Clan in the past.
Kaguya also ascended to the top in one step, obtaining the Nine Tomoe Sharingan, which many Main Family did not possess.
Some of them may have eaten the fruit, but not every fruit can give rise to the Nine Tomoe Sharingan; it depends on the quality.
Without a doubt, the quality of this fruit on Earth is more than sufficient.
Having obtained the Kaguya with Nine Tomoe Sharingan now had the means to protect herself.
Unless a hidden elder from the Ōtsutsuki intervenes, she is invincible.
The baptism of the God Tree Fruit completely freed her from the constraints of the Branch Family, making her immortal.
However, it was precisely because of this powerful force that Kaguya gradually lost her senses.
There's no way around it; with super power, super intelligence will naturally degenerate.
After all, why overthink things when a single punch can solve them?
This is why Kaguya's later actions weren't as exaggerated.
It's simple. Her power is ridiculously strong. You can't expect Kaguya to keep bouncing around like Isshiki, can you?
Would Superman engage in Taijutsu with Steppenwolf?
It's not that you're not strong, but that he's stronger, strong enough to ignore all your actions.
It's impressive to destroy Susanoo and Nine-Tails Mode with just a few punches and kicks by exploiting their weaknesses. However, if it were Kaguya, a single Eighty Gods Vacuum Attack wouldn't just destroy them; it would completely obliterate them, leaving not even a trace of Susanoo.
If anyone had this kind of power, would they still use those low-level Taijutsu?
It's pointless now.
Now, in order to improve Yuzuru's strength and help him evolve faster, Kaguya uses the Amenominaka every day to go to another world to spar with Yuzuru.
Kaguya practically chewed up and fed those Ōtsutsuki Taijutsu to Yuzuru bit by bit.
No one understands Taijutsu better than her; Kaguya has the right to say that, after all, she is the only one who has mastered the Eighty Gods Vacuum Attack.
The strongest Taijutsu cannot be achieved without years of dedicated practice.
Similarly, when facing Kaguya like this, Yuzuru was on the defensive the entire time.
Kaguya possesses the reaction speed to react to Amenotejikara and instantly dodge attacks using Amenominaka. Combined with Kaguya's immense strength, even though she had restrained herself considerably, and with the Taijutsu skills she slowly recalled, Yuzuru went from barely being able to fight back at the beginning, to being forced into a passive defense, and finally to being completely outmatched.
Lying on the ice, Yuzuru didn't want to move a single finger, and her injuries were healing rapidly.
"Your physical strength is already higher than many of the Branch Family."
Kaguya came to his side, knelt down, and gently stroked his face.
"Yeah?"
"You are different from me. Your body is the result of the combined transformation of Natural Energy and Chakra. In the future, you may become stronger than me."
"Stronger than you? Really? I don't believe it!"
Kaguya:...
I have no reason to lie to you.
Yuzuru sat up and lay directly on Kaguya's lap, comfortably closing his eyes.
I believe you wouldn't lie to me.
Upon hearing this, Kaguya's eyes flickered slightly, a faint smile appearing on her lips as she gently stroked Yuzuru's face.
"I will. I will teach you everything slowly, except for Amenominaka and the World-Destroying Infinite Tsukuyomi."
"Hmm, how should I repay you? How about I reward you with a child?"
Yuzuru wrapped his arms around her waist and pressed his face against her waist.
"A child? Sure, but not now. You need to be physically capable of getting me pregnant first."
Yuzuru:...
That was a bit hurtful.
Kaguya smiled and said nothing more.
"Speaking of which, now that you've encountered Isshiki, are you still afraid of him?"
"Afraid?"
Kaguya tilted her head.
"In your words, it's 10/90."
"?"
"It can be divided into nine segments in one second; of course, it's also possible that nothing will be left."
"His two Dōjutsu are too low-level. The Daikokuten is just an infinitely weakened version of the Amenominaka. I can use any of the worlds in the Amenominaka to break through that fragile world at any time."
As for Sukunahikona, this ability might seem troublesome to outsiders, but within the Ōtsutsuki Clan, it's simply laughable.
When you cultivate your Byakugan to a certain level, unless he completely disappears, he'll just appear as a moving little grasshopper to you. After all, the Chakra within his body is just a bright light bulb in the Byakugan.
"Destroying him is simple. Eighty Gods Vacuum Attack and All-Killing Ash Bones —either one will kill him if he encounters it. So, you must master them."
"Alright, it's getting late, I should head back."
Yuzuru nodded, her fatigue gone. She was about to get up from the ground when she was pushed back down.
"?"
You forgot to pay your tuition.