He was dead. Completely dead.
Nagato woke up just recently. Perhaps because of his severe injuries, he turned into what he is now. However, it was temporary. Nagato didn't really lose his mind, he just needed time to recover.
And he was gradually coming to his senses.
The real problem was not the mental state, but the physical state. To save Nagato, Black Zetsu used a large number of Hashirama Senju cells during the head transplant. And then there were complications.
Previously, Nagato's own cells, Hashirama Senju's cells, and White Zetsu's cells seemed to have achieved some kind of amazing balance that only made him stronger in the end. But now Nagato's only head was left, and everything else no longer belonged to him.
This balance has been disrupted. From the neck sprouted countless, tree-like appendages of flesh and blood. On his face, where the scorched flesh had been removed, the wounds had healed. But instead of smooth skin, Hashirama's cells replaced the gaping holes with creepy, distorted faces.
If someone lifted Nagato's head now, they would see that a new face had appeared on the back of his head - the face of Hashirama Senju.
The current Nagato has turned into an ugly monster. And that wasn't all—his strength had also weakened.
The flesh of the White Zetsu, although it was a useful material, had no special power and could not give as much chakra and vitality as Nagato's own flesh gave. And although Hashirama's cells helped, there were too few of them.
Now Nagato didn't have the power he had in the battle with Uchiha Youko. Moreover, due to the loss of most of his own flesh, his body weakened, and Rinnegan began to become a burden to him. Some of his techniques have become inaccessible to him.
But not so long ago everything was going so well.… He could feel his Rinnegan constantly evolving, becoming more docile and more convenient to use. Now everything has gone to waste, it's over!
— Nagato…
Konan looked at him with pain and bitterness from the edge of the bed. His image was still in her mind, that confident, invincible look that never left her thoughts. Back then, she naively believed that Nagato would definitely return with a victory. But it didn't take long, and all that was left of her Nagato was her head.
If it wasn't for Black Zetsu, Nagato would be dead for good. At that moment, she didn't know what to do at all.
After all, how can someone with only one head left survive?
This condition did not last long. By the time Obito and Black Zetsu came to visit him, Nagato had almost completely recovered.
"I lost." Madara, you were right. Uchiha Youko is invincible. He's not a god, he's a monster! A monster that surpasses common sense, a monster that has no place in this world! The only thing left for us is to wait. Wait for Uchiha Youko to die of old age! Madara, be calm. From now on, I will wholeheartedly support our previous plan! Nagato said, admitting defeat.
"It's good that you understood that, Nagato! We told you that we couldn't handle Uchiha Yoko. You didn't listen, and that's what happened. If Zetsu hadn't reacted in time, you would have been dead by now!
"And without you as a vessel, what will become of Rinnegan? What if you really died there, and Rinnegan was destroyed forever?"
Uchiha Obito, arms crossed over his chest, looked at Nagato and mentally shook his head. He had already decided that if Nagato decided to act wilfully again, he would not hesitate to use the mechanism embedded in his body and take full control of it.
—Okay, we'll talk about the past later," Black Zetsu said. — Now there is new information. Hidden Cloud Village has developed a powerful weapon and is preparing to attack Uchiha Youko!
He shook his head and handed Nagato the report. But due to the fact that the nerve endings hadn't fully healed yet, Nagato was almost unable to move. Conan took the scroll and unfolded it in front of him.
—Ha ha ha, impossible! Nagato, without even looking at the report, just laughed and shook his head. "A bunch of fools, nothing more. Uchiha Yoko... It's a monster that surpasses the gods! How can pitiful mortals kill him? This is the invincible Mangekye Sharingan! A power that surpasses even the Rinnegan!
Obviously, the battle on the verge of death had finally broken the back of the self-proclaimed god. He believed in the invincibility of Uchiha Yoko to the depths of his soul.
— And what if it does?.. I secretly entered Cloud Village and found out. The theoretical power of this Lightning Element electromagnetic cannon is simply beyond..." Black Zetsu tried to object.
He himself did not expect that Cloud Village would create something so dangerous and terrifying. A super electromagnetic cannon with a projectile velocity of over one hundred mach... such a thing…
—Impossible, absolutely impossible! Nagato interrupted before Black Zetsu could finish. — Uchiha Youko is invincible, he cannot be defeated, no way! Don't say anything else, Zetsu. These people are just pathetic buffoons. When they realize they can't beat him, they'll retreat! Hsss... ah, my head! Help... gite... me…
He began to shake his head violently, denying everything, like a frightened mouse. He was terrified of Uchiha Yoko. His head had only recently been sewn onto a new body, and the sudden movement dislodged the vertebrae.
Seeing this, Black Zetsu immediately stepped forward and forcefully set his neck.
"Nagato, don't make any sudden movements until your head is completely fused to this body. Especially don't shake or nod your head. I'm afraid you'll accidentally tear it off! There's no life support system on your head right now. If it falls off, you will die completely.
Black Zetsu took out a roll of bandages, wrapped them tightly around Nagato's neck, and then applied the Earth Element to fix her.
Uchiha Obito, who was standing next to her, looked at this pitiful sight and did not know what to say. He realized that Nagato had gone from one extreme to the other, turning into a dog with a broken spine.