Naruto looked at Obito's eyes and said, "Obito… I know how you feel… both of our lives have been ruined by Madara and I just want to say… if you want revenge then it isn't the answer."
Obito looked at him and nodded, with Madara dead he could technically do nothing.
"Wait- ZETSU?!" Obito raged, looking around until Kanjokozui said, "White and Black Zetsu are dead."
Obito resorted to looking around one more time and saying, "Then all is well without Madara's will."
"Madara's will?" Konan said unsurely, "Yes… upon his death he believed his will to be imbuing a White Zetsu, turning the other half into Black Zetsu, which he assumed was his will," Obito explained.
"Wait a minute, now I remember!" Kanjokozui said and continued whilst pausing to think, "Zetsu! The Sage of Six Paths mentioned a dormant army of dead modified beings created by his mother, called… Zetsu… Black Zetsu was never Madara's will, it was… Kaguya's."
Obito widened his eyes and exclaimed, "You mean to me, there is an army of Zetsu created by the mother of the Sage of Six Paths somewhere and Black Zetsu tricked Madara into believing it was his will?!"
All except Kanjokozui paled at the implications and Obito said, "We must destroy those Zetsu or they could fall into the hands of not very good intentioned people…"
They all nodded and said, "I suppose we have a third goal now my pupil, to destroy the Zetsu Army…"
They all nodded and Obito asked awkwardly, "Uhm… if you could?"
Kanjokozui said, "Oh," releasing Obito from the cross and Obito shook his whole body, with Konan asking, "Tobi- I mean Obito, since you are Madara's pupil I suppose you know where the Zetsu Army resides correct?"
Obito nodded saying, "Yes, the army is under an underwater cavern underneath the Gedo Mazo, the Juubi's Husk, let's go."
Obito uses Kamui on all of them to get to the cavern quickly.
Soon they were in the middle of thousands of inactive Zetsu with closed eyes.
"What do we do now?" Naruto asked, with Konan agreeing to his question.
"We simply dispose of them!" Obito said while creating a firestorm that burned the White Zetsu with a murderous smirk, that vanished when the firestorm stopped and the White Zetsu were still asleep.
Naruto smiled and said, "How about I show you how it's done!"
Naruto put his hand high up and created a Rasengan, saying, "Wind Release: Rasenshuriken!"
Suddenly the Rasengan created blades of air around it, resulting in shockwaves. Naruto unleashed the jutsu ways from him, incinerating two dozen White Zetsu.
"If you want to compete, that's fine with me! But keep at least one thousand intact White Zetsu, they are still useful," Obito said, with the other three seriously nodding.
Konan began to dissolve into a whirlwind of paper, shearing the inactive White Zetsu around her to bloody bits, with Naruto employing his Shadow Clones and utilising the Rinnegan, with Kanjokozui wanting to use one jutsu to kill all the White Zetsu in one go but let the children have their fun, only using taijutsu by creating an ethereal clone of himself that was six foot, and creating thousands of hands to grab and crush the White Zetsu easily, with Obito using his Kamui to store a thousand unharmed Zetsu, but mildly straining his eyes, resorting to using Madara's Gunbai and Kama.
-Three Hour Timeskip-
Naruto screamed, "I TOOK OUT TWELVE THOUSAND!" while in his two tails form, with a crater of a Bijuudama behind him and dozens of clones having a tail.
Kanjokozui said, "I took out sixty thousand," Obito said, "I took out twenty thousand," Konan looked at them and said, "I took out seven thousand."
"Naruto! You have lavished and satiated my bloodlust for decades to come?!" Kurama said in a frenzy through one of Naruto's shadow clones, with his power skyrocketing even more, until dying down slowly and Naruto's clones puffing out of existence, running out of juice.
In Naruto's mindscape Kurama collapsed, with what seemed like to be a food coma and the nastiest grin imaginable. Obito waved bits of White Zetsu from his Gunbai, with Kanjokozui unharmed.
"Let's check one more time, we don't need complications," Obito said cautiously with the others agreeing.
Kanjokozui said, "You know what, this place seems nice, once we clear the White Zetsu bits this ginormous cavern could be our new training grounds," these words were said as Kanjokozui looked at the vast expanse which was called a cave, with the whole cavern ten kilometres deep underground below water, with the ceiling reaching up a kilometre, with the area itself to be twenty kilometres, illuminated by nature energy absorbing lichen it was just free underground real estate Kanjokozui didn't want to go to waste.
Obito nodded saying, "I agree, this shall be our new headquarters I suppose…"
Konan said, "There is one White Zetsu awake, attempting to escape!" She ran to the White Zetsu ways away while the other three followed.
They saw the White Zetsu attempting to claw its way upwards but to no avail, looking behind it were the four of them. The Zetsu upon closer inspection wasn't white, but grey.
Surprisingly it said, "AWAY HUMAN?!" the Grey Zetsu screeched.
Kanjokozui send his mini ethereal clone which turned to hundreds of chains to the ground slithering towards the Grey Zetsu, it couldn't escape quick enough and was restrained by the fast chains.
"Who- What are you?" Konan asked.
The question wasn't answered as it attempted to use Mayfly but the chain didn't let loose to its visible shock, shortly after halting and answering the question, "I am mother's last case scenario, if my Black Zetsu brother dies before the goal is achieved then I am released from my slumber to lead the ranks of the White Zetsu Army, but it seems you have destroyed and captured my kin!" Grey Zetsu said scowling,
Naruto asked, "Last case scenario? For what?"
Grey Zetsu didn't budge until Kanjokozui screamed, "WHAT ARE YOUR OBJECTIVE AND GOALS?!"
Simultaneously tightening the chains tenfold, nearly crushing Grey Zetsu, with it feeling intense agony.
"My goal… i-i-is to ri… revive- mother in the- e-event of Black Zetsu's dea- death…" it said quietly.
"Well I'm afraid that won't happen won't it?" Kanjokozui said, planning to crush it.
"Wait!" Grey Zetsu screamed, with Kanjokozui pausing, saying, "What?"
"Do you know the purpose of the Zetsu Army?" Grey Zetsu asked nervously.
"No… Is it to subjugate the world, no?" Obito asked haphazardly.
Grey Zetsu scowled and said, "No it's not! It's to defend it from a far greater threat…"
"And what is this 'threat' supposed to be?" Kanjokozui asked.
"You!" Grey Zetsu screamed.
"You Facelessness, are the bane of Kaguya's existence! Father of Kaguya Otsutsuki!"
Naruto widened his eyes and looked at his sensei, "You're the grandfather of the Sage of Six Paths?"
"Yes…" Kanjokozui said, and continued, "She made an army to eradicate me? Well look how that ended up." they scowled and pointed behind them in the expanse of White Zetsu bits.
"It was my mother's decision, not mine…" Grey Zetsu said with an attempt to shrug.
"Hm… You know if Kaguya is unsealed that means she will become mortal, correct?" Kanjokozui said while peering into Grey Zetsu which everybody felt.
"What? No, that is impossible, she is immortal!" Grey Zetsu said nervously, faltering.
"Is it? I took away her lavish immortality, that is why she wants to destroy me with the Zetsu Army, knowing that she will grow old, taking away her lavish lifestyle and time to play with her human toys," Kanjokozu explained and continued, "She knew the consequences, mating with a human will force me to mortalize her before his seed is ejected into her, making her children albeit mortal but live millenia still. Her audacity to create an army against me! I even gave her the liberty of not showing her age?!" Kanjokozui said with a raised voice, suddenly for everybody else it was hard to breathe, as if they were in the coldest regions of the Earth, but the temperature was still the same.
Suddenly as it came it stopped, with all of them thinking it was only them who felt it.
"Anyways, you shall still die," Kanjokozui said in a tone of finality and seriousness.
"Wait!" Obito said, "He will be useful in my experiments, I mean its colour is different, that's gotta mean something right?"
Kanjokozui sighed and nodded, with Obito using Kamui to send Grey Zetsu in his personal dimension.
"Now that that's settled let's get out of here," Konan said.
They all nodded and Obito used Kamui to exit the ginormous cavern back to Amegakure.
"I am afraid this is where I end my journey with you all," Konan said and continued, "Amegakure is without a leader, I shall take charge and lead in Nagato's memory."
Naruto nodded in understanding with Obito nodding respectfully.
"Sensei, you are the Sage of Six Paths grandfather right?" Naruto asked while nearly outside the gates of Amegakure, headed for nowhere, with Obito keen on listening.
"Yes, I am, I directly created Kaguya whilst she engaged with a human, birthing Hagoromo and Hamura," Kanjokozui explained calmly as if explaining to a child the grass was green, essentially making it feel like Naruto asked a stupid question.
"Can you teach me to use the Rinnegan?" Naruto asked calmly.
Kanjokozui nodded and said, "Yes, but we first need to do something about Obito's other eye socket that has no eyes."
The master-student duo looked at Obito who smiled at them awkwardly who said, "I planned on using only one Rinnegan once I stole Nagato's eyes.
"I-I have something to tell you two…" Obito said, with the other two stopping.
"I partook in the Uchiha Massacre and stole the eyes of dead Uchiha," Obito said looking down.
Naruto sighed and said, "I've had my suspicions that Itachi couldn't've done it all alone. I mean he is powerful but to kill an entire clan?"
Obito nodded and said, "There is a Mangekyou Sharingan that belongs to Indra Uchiha, the first clan head of the Uchiha. I don't want to use it, its abilities aren't even documented and yet I sense it's great power, I feel it yearns to be used! The temptation… is just…"
Kanjokozui said, "Indra? My great-grandson, The Sage of Six Paths' first son with his second wife. If you worry about permission then worry not, you can use them, to fill you in the blank information the right eye houses the ability to reconstruct chakra natures externally, being able to turn a lightning jutsu headed for you into a wind jutsu for instance and throw it back at you, essentially hijacking the jutsu, the left eye has ability of Naruto's former teammate Sasuke, Hinokagutsuchi, manipulation Amaterasu, inextinguishable flames."
Obito nodded, saying, "So I will transplant the right eye to my left eye socket, go on ahead, I'll teleport back once the transplant is complete."
The two of them nodded, with Obito sucking himself in a vortex originating from his eye.
Naruto asked, "Right eye on the left eye socket?"
Kanjokozui explained, "It technically doesn't matter, the structure of both eyes are the same, people just assign left eye to left eye socket and right eye to right eye socket for convenience and lack of confusion."
Naruto nodded in understanding.
They resumed their walk with Naruto on the front, heading for Uzushiogakure.
A.N.
Grey Zetsu 'could' be shown in the future, it's a yesn't matter, Grey Zetsu was supposed to be something else, a villain but I scratched the idea. I didn't want Obito to just have literally one eye so I put the possession of Indra's eyes to him, I wanted him to get Fugaku's since it would make more sense but the existence of Fugaku's MS is contested but the only contested thing about Indra's eyes is its EMS Form, in this case Indra's eyes will be EMS technically, since Indra is closer to the Otsutsuki, originators of the Sharingan, being 25% Otsutsuki and 75% Human, Hagoromo, 50% Otsutsuki 50% Human, Indra's mom, 50% Human 50% Human (100% human), Otsutsuki DNA is technically more dominant potency wise being alien gods (maybe) so trait from Otsutsuki are 50% and Human traits are 50%, but that is just speculation, if you are asking how Indra in this case got the EMS with his brother Ashura literally having no Sharingan let's just say the Sharingan is just like 75% Otsutsuki and 25% diluted human for Indra's Sharingan, with the base 1 Tomoe Sharingan being 25% Otsutsuki and 75% Human, all the numbers are just baseless suppositions, believe them or not I wouldn't care more or less. Scientifically you CAN put a left eye on a right eye socket, but realistically you can't implant eyes in real life but this is Naruto since they are glorified light bulbs. Kanjokozui's relationship with Kaguya and reason to create the Zetsu Army will void the need for the 'Main Otsutsuki Branch" and remove Momoshiki, Kinshiki, Urashiki, Shibai, and etc from the equation altogether, I didn't want to do precarious thing to just add the Otsutsuki Clan relatively politically correct, I don't want the other Otsutsuki in Boruto to exist in this fanfic.
Toodles :)