When the attack made contact, a sphere of lightning and wind shredded everything within its domain of effect to pieces. Ino and Karin didn't waste this time and shot their own techniques into the domain of the Storm Style Rasenshuriken. Unlike the others, they knew about the powers Chojusen had completely. The others might be afraid of hurting Chojusen and were waiting to see the result of Naruto's attack, but Ino and Karin were shooting off Lightning Javelins, Flame Bullets, and Water Bullets to potentially catch Kaguya off guard.
They succeed, as she hadn't been expecting another attack while the Rasenshuriken was still in effect. Chojusen also managed to get a couple punches in before Kaguya regained some of her momentum back and starting countering him again.
Kakashi used his Kamui to become intangible and passed through the ninjutsus that landed on Kaguya and slashed at her with her Susanoo's sword. He then fled back before Kaguya could try to harm him with Chojusen further blocking her attacks.
Kaguya started to see people other than Chojusen as a serious threat and decided to start killing them off to help improve her chances of beating Chojusen. Her thoughts were interrupted when Hinata shot off a beam of glowing light from her left eye that managed to cut off her left arm. Kaguya muttered "Reincarnation energy..."
The Tenseigan was very dangerous and if Chojusen weren't added to the equation, it would definitely be the biggest threat to her, so Kaguya decided to start her extermination with Hinata. She teleported out of Chojusen's reach, something that had happened countless time through their melee exchange. Chojusen didn't think much of this teleportation until he noticed that Kaguya teleported twice. The first time was a feint to throw him off guard!
The second time she teleported she slashed at Hinata. Chojusen's clone managed to push Hinata out of the way and take most of the damage, but Hinata lost both her arms and eyes to Kaguya's assault. Chojusen then felt a tremor through his soul as he watched Kaguya teleport again; this time it was in front of Karin…
He felt time slow to a crawl as he watched Kaguya's hand approach Karin's chest. He screamed in his mind and pushed himself to the limit doing everything in his power to stop Kaguya before she could deal the blow, but nothing helped. He had already used Gravity to is maximum effect on his body and changed his elemental coating to lightning. But he still wasn't fast enough. Even if he passed through a dimensional gate he wouldn't have time to block Kaguya and a direct teleportation would only be suicide.
Deep down in his heart he hoped for a breakthrough to come and save him like they always did. The breakthrough came… but only when he assumed the worst.
Everyone watched in shock as Kaguya's hand passed through Karin's body and she crushed her heart in her hand. Karin coughed up some blood and limped over slightly.
At this moment, Chojusen felt regret. He regretted not being strong enough to beat Beat Kaguya without resorting using all his powers. He regretted dragging the fight on for this long and allowing Kakashi and company the time to come to the battlefield. He regretted wasting his time, all those years he could have been training with his clones and all those days were he lazed around in the lake of his personal dimension when he could have been improving his strenght to avoid this situation from developing. Last but not least, he regretted… not being able to spend enough time with Karin…
In this moment where time had basically stopped and Chojusen fell into an abyss of regret. His psyche changed ever so slightly and his grasp over time rose by another step. With his time law principle of restoring mastered, the Third Stage's ability of his Fiendgod eyes returned and Chojusen erupted with enough force and strength to blow up small cosmic bodies.
His hands that were covered with black fiendgod chakra and purple thunder, ripped Kaguya's hand out of Karin's body and then send a punch so destructive Kaguya's way, the void was disturbed and visibly shook. Chojusen's breakthrough only netted him one additional second with his Fiendgod eye's third ability so he only accomplished this one punch before time started flowing at its normal rate.
Chojusen caught Karin in his arms and finally remembered that she was at the Demi-Immortal level while using her Elemental Sage Mode. It was just that the scene of watching her lose what normal humans would consider a vital organ, shocked him silly. Demi-Immortals were a cut above normal humans — or whatever species they originated from. Just being one gave you various benefits and disadvantages.
Just like losing a bit of fertility was a side effect of being a Demi-Immortal, losing the need of vital organs was another side effect. At the Demi-Immortal level losing things like the brain and the heart would not kill you; at least not immediately. Ino and Karin at their level could survive for maybe five or six minutes without their vital organs before dying; plenty of time to restore their wounds unless they were totally incapacitated. Even if Chojusen didn't arrive like he did, Karin would have been fine with her Temporal Restoration and Water Healing when Chojusen fought Kaguya off of her.
Chojusen made Karin good as new in less than a second from the time she lost her heart, so she barely felt any pain from the whole ordeal. Chojusen's clone was more than strong enough to heal Hinata as she was no where near the Demi-Immortal level and with a Yin-Yang Recreation, Hinata regained her arms and eyes.
With Karin and Hinata healed, Chojusen teleported to Kaguya and was preparing to kill her off, he had originally planned to seal her with Naruto, Sasuke, and Hashirama's help, but making an attempt at Karin's life sealed her fate in Chojusen's eyes.
That last attack from Chojusen destroyed more than just Kaguya's body, her spirit and chakra pool had also been seriously damaged; currently she was nothing more than a husk, defenseless and waiting for death.
As Chojusen created a supernova in one hand and made preparation for the lightning filled with his other hand, he was stopped by Naruto. Naruto said "Wait! Don't do it!"
Chojusen narrowed his eyes at Naruto's words "After what she did, you still think we should let her live?"
Naruto said "Well, I think she doesn't deserve it… wait just hear me out! Ok?" When Chojusen heard Naruto say he thought she didn't deserve it, Naruto felt a cold and penetrating gaze stab through his psyche.
"Fine." Chojusen's voice had no emotions.
"It's best if Kurama explains it, so just take my hand."
Chojusen complied with Naruto's wishes, wondering what this Kurama could possibly say to convince him to not kill Kaguya. Chojusen was then pulled into Naruto's mindscape, where he saw a familiar looking nine-tailed fox.
Kurama said "Greetings… I still haven't thanked you for helping me regain control all those years ago."
"Its fine. Now, if you will, please explain why naruto has suggested that I don't kill Kaguya."
"You are a practitioner of yin-yang, so it's best if you just see for yourself." Kurama then extended one of its claws and transferred some information into Chojusen's head.
To Chojusen's surprise, he actually received the formula for a sensing technique. Chojusen only needed a single attempt to use the technique correctly; his own Origin Detection technique worked of Yin and Yang law principles, so this "lesser" technique was too easy for Chojusen to learn.
[Host has learned the skill: Essense Sensing
Essense Sensing: The user uses Yin and Yang Law Principles to read the essence of a person. Aside from being a great detecting and sensing technique, reading someone's essence allows the user to see their emotions personified. Current Effect: Only Mid-tier Immortals and below can have their essense forcefully read.]
Chojusen thanked Kurama for the wonderful technique and left Naruto's mindscape. Presumably, he was awarded that technique to see Kaguya's emotions for himself, so he did just that. What he saw made him understand why Naruto and Kurama would stop him; he even felt a bit bad for Kaguya.
Now that Essence Sensing was in full effect, Chojusen could see a towering black mass spewing out endless hatred, rage, pride, bitterness, and countless other negative emotions, while a small white and weathered soul sat in the center of that black mass doing its best to not get consumed.
The black mass seemed to have originated from Black Zetsu, which up until this time had been quietly hiding in Kaguya's robe. With Essence Sensing, Chojusen concluded that the two had completely different soul signatures that came from the same source somehow.