The Chosen of Tengri(Fate Stay Night)

 The first thing Shirou felt upon waking was the ache in his arms. It was a dull, persistent throb that ran from his shoulders down to his fingers, as though he'd spent hours lifting and swinging something heavy. He flexed his hands experimentally, frowning at the sensation.

"What...?" he muttered, sitting up in bed.

The dream was gone, as it always was—its details slipping away like sand through his fingers. But the sensation of heat, the echo of metal striking metal, lingered faintly in his mind.

Shirou rubbed his temples, trying to piece together the fragments. He remembered... fire. An anvil. And a voice—sharp, commanding, unyielding.

"You must forge your strength," it had said.

Shirou shook his head, swinging his legs over the side of the bed. He stood slowly, stretching out his sore limbs. Whatever had happened in his sleep, it felt like he'd been through another training session.

By midmorning, Shirou found himself in the backyard, wooden sword in hand. The air was cool and crisp, carrying the faint scent of autumn leaves.

Kiritsugu stood nearby, his arms crossed as he watched Shirou prepare for another routine. His sharp eyes scanned Shirou's stance, his posture, searching for any imperfections.

"Ready when you are," Kiritsugu said, his tone calm but expectant.

Shirou nodded, gripping the sword tightly. He moved into the first stance, the weight of the blade feeling lighter than ever.

When he began the routine, his movements came faster, smoother. Each strike flowed seamlessly into the next, the transitions between steps sharper and more precise. His footwork, once hesitant and uneven, now carried him with confidence.

By the time he finished, he was breathing hard but steady, his arms steady despite the effort.

Kiritsugu frowned, stepping closer. "You're faster," he said. "Cleaner. Where did that come from?"

Shirou blinked, glancing at the wooden sword in his hands. "I... don't know. I just practiced like always."

"That's not practice," Kiritsugu said, his tone firm. "That's progress—real progress. And it doesn't happen overnight."

Shirou shifted uncomfortably under his guardian's scrutiny. "I don't know how to explain it," he admitted. "It just... happens sometimes. Like my body knows what to do before I think about it."

Kiritsugu studied Shirou for a long moment, his gaze sharp. "This isn't the first time, is it?"

Shirou hesitated. He thought back to the other times it had happened—the moments when his hands moved before his mind could catch up, when instincts he didn't remember learning guided his actions.

"No," Shirou said finally. "It's been happening more and more. Like something's changing, but I don't know why."

Kiritsugu exhaled slowly, his expression unreadable. "This isn't normal, Shirou. Progress like this doesn't just appear out of nowhere. Are you hiding something from me?"

Shirou's eyes widened. "No! I'm not hiding anything. I swear."

Kiritsugu's gaze softened slightly, but the concern in his eyes didn't fade. "You've been dreaming a lot, haven't you?"

Shirou nodded, his grip tightening on the sword. "Yeah. But I don't remember them. Just... pieces. Like I'm doing something in my sleep, but it's gone when I wake up."

"Something," Kiritsugu echoed, his voice quiet.

"I wish I could explain it," Shirou said, frustration creeping into his voice. "But it's not like I'm trying to hide anything. It's just... happening."

Kiritsugu sighed, running a hand through his hair. His health had weakened him over the years, but his instincts remained sharp, and something about Shirou's rapid progress didn't sit right.

"Whatever it is," Kiritsugu said finally, "it's changing you. And fast. Faster than I'd like."

Shirou lowered his gaze, the weight of Kiritsugu's words pressing down on him. "Do you think it's... bad?"

Kiritsugu hesitated, his brow furrowing. "I don't know. Not yet. But I don't like not knowing what's happening to you."

The words hung in the air, heavy with unspoken concern.

That night, as Shirou lay in bed, Kiritsugu's words echoed in his mind. He stared at the ceiling, his thoughts swirling.

What is happening to me?

The question remained unanswered as sleep claimed him.

Far away, in the dream world, the forge awaited. Its fire burned steadily, the anvil gleaming beneath the starlit sky.

Genghis Khan stood beside it, his expression unreadable as he gazed into the flames. "The boy is changing," he murmured. "Soon, he will be ready."