Free The Destruction of the World by Fire by Shiden Kanzaki

Suddenly, Yuzuki jumped on Tamaki’s shoulder and leapt upward, flying high over Rentaro and Tina. Her trail sparkled with light.
    What was that?
Rentaro had no time to resolve the question in his mind as Yuzuki landed on the ground at his back. Realizing they were surrounded, Rentaro narrowed his eyes. “Tina!”
    “Okay!” said Tina. In the midst of the confusion, Rentaro and Tina quickly stood back to back.
    Yuzuki and Tamaki kept a fixed distance away as they started circling Rentaro and Tina. It was as if they were two sharks, tenaciously circling their prey, instilling fear as they waited to sink their jaws into them.
    Rentaro and Tina also changed positions as they matched the slow movements of the Katagiri siblings. Through their shirts, he could feel the heat of Tina’s body and the damp sweat on her backin response to the slowly mounting pressure. They would certainly be at a disadvantage in a long fight. An impromptu pair would start to unravel the minute they started feeling nervous.
    In order to pick a fight with the brother, Rentaro dove forward and shortened the distance between them in an instant. It was a test: Tendo Martial Arts First Style, Number 8—
    “Come on!” Tamaki swung an arm that was about as big as Rentaro’s thigh and Rentaro matched his movement. “
Homura Ka
—!”
    “Ahhh!”
    The meeting of Rentaro’s and Tamaki’s fists sent shock waves across the entire gym. The heavy blow sent numbing tingles up Rentaro’s artificial arm, and he shut one eye without thinking.
    In Tamaki’s style of killing, he definitely did not have the skillful technique Rentaro had. However, the difference in their physique and muscle strength was enough to be a deciding factor in their fight. In addition, the attack power of the knuckledusters hanging from Tamaki’s fists was undervalued.
    However, at this point, Rentaro was still misreading the threat of the Promoter named Tamaki Katagiri.
    Rentaro then noticed Tamaki’s knuckledusters and guiderail—or something that looked like the grooved chain of a bike—moving.
Wait, were those even knuckledusters?
Seeing the compact power unit on the back of his hand, Rentaro got chills down his spine.
I see, that’s a—
    Tamaki grinned, and Rentaro hurriedly tried to pull his fist back, but it was too late. With a sudden explosive sound, the chain that looked like a knuckleduster started to rotate, and when their fists met, it shaved off part of Rentaro’s fist.
    “Arghhh!” Rentaro’s brain registered the seething pain, and he stumbled forward. Looking at his right fist, he saw that the artificial skin had been completely shaved off, and the Super-Varanium inside was peeking through. Since he hadn’t cut his pain nerves before the fight, a wave of injury so intense left his mind feeling spent. If he had used his real left fist, his hand would have been a terrible sight.Rentaro lifted his face and gritted his teeth as he looked at Tamaki. What Tamaki had on his hand was a grinder, a rotating file. No, there was a more precise name for it as a weapon—“A Varanium chain saw, huh…?”
    “That’s right! Took you long enough to notice, boyo.” Both of Tamaki’s fists buzzed like a nest of angry bees. “But you were hiding the hardware inside you from me, too. Now we’re even.”
    Rentaro quietly hid his exposed Super-Varanium fist from the eyes of the spectators. Tamaki’s fist could be swung in defense in addition to the obvious offensive attack. Even so, if Rentaro did not attack, the situation would just get worse.
What should I do? What should I do?
    “All right, I’m coming!!” Tamaki shouted.
    With a terrible, rotating buzzing sound, the two fists rushed at him. Rentaro stepped backward and escaped three punches by a hair, only to have Tamaki’s combat boots fly upward, kicking at him with the heel. As Rentaro blinked, he saw that there were chains wrapped closely in the pattern of Tamaki’s boots, and Rentaro felt chills