Under the effects of a massive amount of Natural Energy, Kakashi's cells began multiplying rapidly and becoming keratinized. More specifically, his body quickly swelled as it hardened like stone.
The light of the Lightning Blade rapidly dimmed.
Although Natural Energy was a powerful tonic, most ninja couldn't handle too much of a good thing. Without gradual training, how could an ordinary ninja suddenly withstand such a large amount of Natural Energy?
Yuzuru's little trick had worked mainly because he'd used himself as bait. Though the Lightning Blade had pierced his body, it had also pinned one of Kakashi's arms. A ninja who couldn't bring his hands together couldn't form hand seals or use jutsu.
Battles between ninja hinged on both strength and intelligence. Kakashi had ultimately fallen for the trap. Whatever his true strength, he hadn't been able to bring it fully to bear during their brief exchange.
"You're still too young. Your fifty-fifty technique clearly isn't fully mastered. Cough, cough..."
Yuzuru coughed a few times, spitting up a large amount of blood. He staggered back several steps, then, gritting his teeth against the pain in his chest, pulled Kakashi's arm free.
Since he'd just used a move that could have killed them both, Yuzuru was in bad shape too. He could feel his strength and body heat rapidly slipping away. Kakashi had deliberately avoided his vital organs, but if Yuzuru didn't treat the wound, he'd soon lose the ability to breathe.
His chest had been pierced clean through, and blood poured freely from the wound. Yuzuru felt cold all over.
"Now's the perfect time to try treating myself..."
Yuzuru had studied Medical Ninjutsu before, but only its basic principles. He hadn't mastered Yang Release Transformation and couldn't use actual Medical Ninjutsu, but he hoped to use Natural Energy to