Sometimes, you really can't blame Black Zetsu for hating Obito Uchiha. Compared to the meticulously thorough Emiya Shirou, Obito's actions were always a bit... idealistic.
He had a knack for turning a perfectly good plan into a chaotic mess.
Fortunately, Kisame Hoshigaki's professional ethics were solid. This ANBU from the Mist Village learned Obito's identity but had no immediate intention of betraying him.
He was even willing to listen to his orders.
"Assassinate the Fourth Mizukage," Kisame mulled over the order delivered by Kabuto Yakushi. "Then join his organization as an S-rank rogue ninja and help him investigate it? Sounds a bit strange..."
"It is strange," Kabuto agreed, frowning. "It seems you don't intend to refuse?"
Going from a high-ranking ANBU to a rogue ninja was a life-altering decision.
"For me," Kisame said, stroking his Samehada and wrapping bandages around the blade, "in this fake world, my life has no meaning anyway. At least that guy can give me a little hope."
"Perhaps..." Kabuto adjusted his glasses, holding back what he really wanted to say.
He wouldn't recruit for Shirou without permission. Even if he thought Kisame was a worthy partner, he'd only mention it in his report.
"Perhaps what?" Kisame asked casually.
"Nothing," Kabuto smiled, a genuine twinkle in his eye. "Everyone finds their goal sooner or later."
"It seems you've already found yours," Kisame said, a hint of admiration in his voice.
He picked up his greatsword. "Unfortunately, everything in my life is worthless. The little hope I have also seems to be an illusion."
"Are you going to assassinate the Mizukage now?" Kabuto asked, surprised by his speed.
"First, I'll find a suitable spot," Kisame's steps paused. His voice was faintly melancholy. "Letting Lord Mizukage die sooner is a good thing. Many people in this village hope he dies soon, perhaps including Lord Mizukage himself. At least he won't have to live in this world that has never touched reality."
Yes, the Fourth Mizukage probably did wish for an early death.
Having been controlled by Obito for so long, presiding over the Bloody Mist Village where ninja graduates were forced to kill their comrades... it was a living hell.
It wasn't until Zabuza Momochi killed his entire graduating class that the gruesome exam was finally terminated. But even then, the village was not at peace.
As the Mizukage, Yagura had become the instrument of his village's destruction. His heart must have been in constant torment.
"Is there anything I can help with?" Kabuto offered.
"No need. I will take him down," Kisame bared a mouthful of sharp, shark-like teeth, as if assassinating a Kage was a trivial task.
And, as it turned out, it was.
-----
On the coast of the Land of Water, a torrential downpour fell.
Kisame stood in the rain, Samehada in hand. The Mizukage's guard squad lay scattered, and Yagura's body lay in the center of the battlefield.
Kabuto, holding an umbrella, had watched the entire battle. He hadn't expected Kisame's strength to be so formidable.
"What terrifying power," he murmured, his gaze piercing through the rain. "As expected of the legendary Tailless Tailed Beast of the Mist."
Kisame poked Yagura's body with his sword, unimpressed with his own achievement. "It's just that my ability happens to counter his."
As a member of the Hoshigaki clan, he could naturally absorb chakra, and his strongest Water Style jutsu only grew more powerful by feeding on his enemy's attacks.
The Fourth Mizukage, a jinchuriki with immense chakra, was practically an all-you-can-eat buffet.
To make matters even easier, Yagura had broken free from Obito's genjutsu just before his death and chose not to resist the assassination by his own ANBU ninja
It was almost effortless.
"Let's go," Kisame said, calling for Kabuto to take him to Obito.
As they left, Kabuto paused and took one of Yagura's severed hands. This bit of flesh would be enough for a future Impure World Reincarnation.
-----
The assassination sent shockwaves through the Mist Village. The ninjas were a mess of joy and sorrow. They were happy the Bloody Mist Policy might finally end, but worried about the power vacuum.
Fortunately, the village elder, Genshi, stepped in to stabilize the situation, issuing a bounty on Kisame while simultaneously abolishing the hated policy.
"Isn't Lord Kisame a hero?" a female ninja objected. "Just like Zabuza, who destroyed the graduation exam! Do we have to issue a wanted order?"
"It's unavoidable," the old man shook his head. "If assassinating the Mizukage can be forgiven, the Mizukage will lose all authority. Besides, he knew Kisame would likely have no desire to return anyway."
For him, maintaining order was paramount.
-----
In Orochimaru's base in the Land of Sound, Kisame finally met Obito.
"I'm sorry for deceiving you," Obito said with surprising sincerity. "Although I represent Madara's will, I needed to hide my identity."
"It doesn't matter," Kisame replied, his tone flat. "There's nothing real in this world anyway. If you truly represent that lord's will, then seeing your plan succeed is enough for me. Next, I am to join your organization and monitor it, right?"
"That's right," Obito nodded. "Before you join, I'll tell you the situation. A great figure who once collaborated with Madara has been resurrected. He has forcibly taken over my organization."
"I'm a bit worried he isn't taking the plan seriously enough, which is why I need you inside."
"Interesting. Who is this great figure?" the corners of Kisame's mouth turned up.
When Obito said the name, his own face darkened. "Emiya Shirou. I believe you should have heard of him."
Kisame's face changed abruptly.
Don't be ridiculous!
How could that man do such a thing?
Even in the Land of Water, the stories of Emiya Shirou were widespread. The Second Mizukage had even cited his admiration for Shirou's beliefs when he called for an end to the First Great Ninja War.
How could such a respected man be the person behind a dangerous organization?
"This is really making it harder and harder to tell what's real and what's fake," the smile on Kisame's face turned bitter.
He couldn't comprehend it.
He had never thought a person like himself would one day have an intersection with Emiya Shirou.
Obito understood.
The first time he learned Shirou had guided Madara's Project Tsuki no Me, his feelings had been exactly the same. "Don't worry about his identity. He's just an old fossil from the ancient era."
"Although in a sense, it was he who proposed the project, in my opinion, he is not truly trustworthy."
"Be active outside for a while. The Akatsuki is in dire need of manpower. They should soon invite you, an S-rank rogue ninja, to join."