What was happening was not part of the plans of Obito and Black Zetsu. It was pure improvisation, an unforeseen and dangerous malfunction in a well-established mechanism. They knew, of course, that Nagato was studying Uchiha Yue's abilities, trying to find vulnerability in them, but they didn't give it much thought, secretly laughing at his futile attempts.
Even the fleeting regret that Orochimaru could not be involved in the research evaporated when he called Senju Tobirama. Let them figure it out for themselves. Black Zetsu was pretty sure that, given a little more time, he would create the necessary sealing technique alone.
—Haha... no, it can't be. Nagato is no fool. He wouldn't do such a thing without being sure of victory. He's not suicidal, is he? Ha ha ha!
—Zetsu, calm down! We have to believe in Nagato! He will win!
Obito laughed nervously. The laughter turned out to be stifled, almost hysterical, and panic was clearly audible in this feigned bravado. He was trying to convince himself, not so much Zetsu.
"...It's hard to say.
Black Zetsu froze for a moment, and then slowly shook his head. His stomach dropped. If Nagato succeeds, excellent. But if he loses... the problem won't just be the loss of precious eyes. The problem will be the death of the whole world. And this time, he, Black Zetsu, would not have another chance.
No... maybe it will. But without Rinnegan, with Obito completely broken... would Obito want to continue letting someone into Kamui's space to wait out the end of the world in the hope that Uchiha Yue would die of old age?
It's hard to say.
It turned out that this was his last chance. If Nagato doesn't come back, then the day Yue's power covers the planet, Black Zetsu will come to an end. No, he couldn't have died. Absolutely not.
He must survive. He must save his mother!
Black Zetsu's gaze glared at Obito, his only sighted eye. There was only one way to survive, and that was to hide in Kamui's dimension. And for this, apparently, we will have to deal with Obito.
You can't kill him. Just take the eye, and sharpen him. In addition, he will need other people to continue the plan.
Especially that boy, Uchiha Sasuke.
The Uchiha clan was practically exterminated. Sasuke and Obito are the last two. An almost extinct species that needs to be protected. There was Yue, of course, but he didn't count.
In order to get a new pair of Rinnegans one day, it was vital for him to ensure the survival of the clan.
Damn Uchiha Itachi!
Black Zetsu was overwhelmed by a wave of belated regret. If he had known earlier, he would have forced that idiot Obito to stop mad Itachi. Such a traitorous, ungrateful psychopath should have been killed on the spot. And what now? A monster named Uchiha Yue has appeared, the clan is on the verge of extinction, and the only pair of Rinnegans is about to be destroyed.
Black Zetsu didn't know yet that Uchiha Sasuke Konoha had already almost broken him, both physically and mentally. If he had known about it, he probably would have died of rage on the spot. Uchiha Obito went from being "irreplaceable, but with a backup option" to becoming an absolutely unique specimen. His death will mean that there will never be a chance for a new Rinnegan.
—Damn it, Zetsu, what do we do now?!" If Nagato loses, our plan will collapse!
Obito grabbed Black Zetsu by the shoulders and, shaking him furiously, screamed with the desperation of a drowning man.
"How should I know?" It's all because of you, Uchiha Obito, you damn idiot!
Obito's scream was the last straw. Rage, which had been cold and calculating until that moment, boiled up, scorching Black Zetsu's mind. He kicked up his leg and knocked Obito down with one sharp kick.
- damn it! IT'S ALL YOUR FAULT! If you hadn't conspired with that bastard Itachi back then to arrange a massacre, if you hadn't touched civilians like Uchiha Yue, would it have come to this?!
"Uchiha Obito, I'll... damn you... DAMN you!" If it weren't for you two idiots, Uchiha Yue would have remained a philistine, he wasn't even a Shinobi! Tell me, WHY?! Why was it necessary to touch civilians when destroying a clan?! How did they bother you? Have you eaten your rice?! What did ordinary people have to do with your war games?! Answer me! damn it!
- "What to do now, what to do now"… And where were you with your questions when you and Itachi started this massacre?! Eh?! You asked me what to do before you set him off against your own clan? Now you're asking me, and I don't know what the hell to do!
— Well, that's great! Just wonderful! The world is on the verge of destruction, Nagato is about to die, Rinnegan will be lost, and the world you so wanted to create will never come! It's over, and it's your doing, you idiots! And you're asking me what to do?! And I want to ask you why the hell you touched someone who shouldn't have been touched!
— Now there is only one thing left — to pray! Pray that Nagato wins! That he would kill Uchiha Yue!
Black Zetsu, grabbing Obito by the collar, screamed in a frenzy, venting all his rage and impotence. What to do? What's the point of that now?! Is he a god to know the answers to everything?
The destruction of the Uchiha clan was never necessary. It wasn't in his plans at all. If they had just followed the original plan, a monster like Yue would never have appeared. Perhaps by this time he would have already achieved his goal. I would have resurrected my mother.
And all because of those two idiots. Fine. It's all over now.
Black Zetsu's hands opened. He let go of Obito and sat down heavily on the ground. The anger drained away, leaving behind only a scorched void. He couldn't really touch Obito. After all, there was still Sasuke, but... what if?
What if Uchiha Sasuke turns out to be infertile?
Obito stood silently under this torrent of accusations with his head down. He wanted to object. To say that Uchiha Yue wasn't killed by him. That on that day he…