A cold, gentle breeze blew in from the window.
Emiya Shirou felt no chill; his reanimated body's senses were no different from a dead person's. Still, he closed the window like a living person might. Perhaps this was the only way to feel alive.
The house was arranged by Senju Tobirama. Shirou didn't need a room to rest, but he needed a quiet environment. His excuse was that he needed to observe the medical ninjutsu of this era. An ANBU member was stationed outside, not to monitor him, but to protect him and await his requests. Tobirama believed he could control Shirou with a single thought but maintained a level of respect, hoping Shirou wouldn't see the Impure World Reincarnation as a form of control.
"Don't stay up late. Rest early," Shirou said to the ANBU hidden below the windowsill. "Just bring me a map of the ninja world tomorrow morning."
The ANBU hesitated but, remembering Tobirama's orders, flickered away to report the request.
Shirou's mood calmed. "I clearly only left it one path," he muttered, toying with the lamp wick. "Why hasn't my ally come to see me yet?"
Black Zetsu... why haven't you come to find me? If your mind has been honed by a thousand years, you'll surely understand that your old ally is your only choice. It can't be... that you're still as simple and easy to deceive as you were a thousand years ago, right?
The candlelight flickered. A pitch-black shadow appeared on the wall. A creature quietly emerged from the ground. Just as Shirou was getting worried that Black Zetsu's mind hadn't improved, its figure appeared silently behind him.
"It's been a long time... Lord Wei Yuan," its sinister voice whispered.(name Wei Yuan means Great Source or Great Origin)
"Lord Wei Yuan" was a particularly close and respectful address. Usually, only the slug Shirou had raised from a young age would use it, but Black Zetsu, considering their relationship very close, would occasionally use it as well. Though in its heart it had always considered Shirou its pawn, it would never dare to say so to his face. After all, the power gap between them was huge. They were once partners, not master and subordinate.
"This voice..." Shirou's body stiffened in disbelief, his fingers freezing on the lamp wick.
"It's me," Black Zetsu's voice was ethereal as its figure once again submerged into the ground. "If you still remember me, the one who shared a common dream with you but was ultimately abandoned by you, Lord Wei Yuan."
"I'm sorry," Shirou said, a look of guilt on his face. As he lowered his head to express his apology, he saw Black Zetsu emerge from the ground in front of him.
"You didn't expect this, did you, Lord Wei Yuan?" Black Zetsu looked at the shame and shock on Shirou's face, its mood gradually relaxing into a satisfied smile. "I didn't expect it either. After living alone for so long, I would actually have the chance to see Lord Wei Yuan from over a thousand years ago."
"Indeed," Shirou gazed at it. The current Black Zetsu was taller than it was a thousand years ago, more like an adult. "You've grown taller... Black Zetsu," he said, a gentle smile on his face, just like the countless times he had praised it and the slug many years ago.
The smile on Black Zetsu's face froze. Hearing the praise, its original intention to question him faltered. For a moment, it didn't know what to say. This guy... why is he still like this! It had prepared to turn its most venomous words into the hardest fist to brutally awaken Shirou, but the fist met cotton before it could even be thrown.
Before Black Zetsu could wound his kind heart, Shirou seemed to have already been hurt. A look of sadness appeared on his reanimated face. He began to toy with the lamp wick again, his finger reaching into the flame, making it flicker and dance. "This is nice. After more than a thousand years, I actually have the chance to see a former companion." His voice seemed happy, but his face held an unspeakable sadness. "Black Zetsu... the ninjas of this era are truly geniuses. To be able to use the body specimen I left for future generations to resurrect me."
"Are you angry, Lord Wei Yuan?" Black Zetsu sneered, unceremoniously joining him in mocking this world. "This is the worst of times, isn't it?"
"Is it?" Shirou looked up, his voice self-deprecating. "The ninjas of this era told me that this is the best era they've had in a thousand years."
"That's right!" Black Zetsu's face turned sinister. "For the descendants of despicable people, this is the best era! Those who obtained chakra started one war after another, creating the thousand-year-long Warring States period. Even though I have spread your story throughout this millennium, letting ninjas know that the power of chakra is meant to save the suffering world, they still use it to fight endlessly." Naturally, it hid its own role in instigating those wars.
"Lord Wei Yuan," a strange smile curved on its lips. The atmosphere was right. It decided to ask the question it had wanted to ask for over a thousand years. "Seeing the endless fighting... hearing about the chaotic thousand-year Warring States period..." It watched as Shirou's face grew uglier, its mood growing more pleased. It decided to deliver its fatal blow. "Now, Lord Wei Yuan, do you regret believing Asura's foolish words back then?"
Shirou fell silent. In Black Zetsu's eyes, this was a speechless admission. The smile on its lips grew wider.
"Perhaps," Shirou suddenly spoke, his voice ethereal and hollow, "everything is still unknown. I remember Asura promised me that he would quell the conflicts brought by chakra, that he would protect the weak, that he would make chakra a power to save the world, and that he would not stop even after his life ended. Originally, I had thought this world was absurd beyond cure. But today I met this generation's reincarnation of Asura's chakra. This generation's reincarnate is named Senju Hashirama, and he happens to be a descendant of Asura."
He continued, his voice full of admiration. "I vaguely remember the surname Senju. It was a gift I gave to Asura, one of the surnames I helped him choose. It means that people unite, gather together, and extend their hands. The power of a thousand hands can quell all future disasters. I heard about Senju Hashirama. He has united many people, quelled a thousand years of war, and ended the chaotic Warring States period."
The sinister smile on Black Zetsu's face froze.
Wait... you still believe in Asura? How are you still so simple and foolish! Wait... you've already been tricked once! How can you still believe in Asura and his descendants? Wait... don't fall for their tricks! They are all deceiving you! Can't you just obediently be deceived by me!