The two were now outside. One wielding a safer weapon than her toxic nichirin sword; a simple kendo katana. She would still use the same techniques, but it wouldn't kill the newly named demon. Nova on the other hand was trying to figure out exactly what power he had. It felt more than fire, but that's all he could actually do without much thought. He'd have to experiment with it in his own time.

Nova didn't have the luxury of doing that now, but that wouldn't stop him from attempting to try his own things during combat. In the time he had while waiting for the overcast clouds to be placed over the school, a system he still found a little weird, he thought of a few ideas that used the demon's natural malleability to his advantage. It was a long shot, but he was going up against one of the strongest Demon Slayers at the moment. He believed that a small advantage would allow him to at least get a hit in.

In the past, all attempts to make something new have failed. Although he's making a great time with his creation training, he still hasn't made a single fan that can block a nichirin sword. He's been so close before, but the pieces ended up breaking after a period of time if they were small.

He was about to do something way more simplistic than that since it'll be connected to him the entire time. Still, he was going against a Hashira of the Demon Slayer Corps, one of the strongest warriors in the world; only surpassed by Celestia herself and the ferocious dragons. Nova would be Lying if he said he wasn't scared, but he was scared that she'd rip him to pieces to get her anger under control. Sure he can regenerate, but that doesn't mean it isn't painful.

Nova couldn't hesitant or he'd lose, but he knew he was going to. This was less of a training duel and more of cathartic relief for Shinobu, but he was at least going to put up a fight. He took a deep breath in, which Shinobu took notice of, before leaning forwards. Nova's back began to move and contort in ways it wasn't supposed to before two spine-like tendrils that ended in sharpened tailbones.

Shinobu paused as she observed the new appendages coming from his body. She placed a hand on her chin as the thought, a habit she had since she was a kid. "He makes up for his lack of control of his Blood Demon Art by making a biological weapon he has total control of. He could even coat those tendrils in a fire for added effect. Smart." Shinobu thought before she saw Nova lying face-first on the ground.

Nova was out of energy. He used a lot to heal earlier that day after getting a dose of vitamin D. He wasn't going anywhere any time soon if she doesn't replenish that energy. Normally, it's easier said than done, but he could just sleep and everything would be fine. That didn't stop Shinobu from chuckling under her breath about it. She couldn't explain why it was so funny to her. She did see it as a little unfair to fight him if he couldn't even show her him at his best.

Shinobu walked over to Nova's unconscious body to take him somewhere safe to sleep. Just as she was about to pick him up, one of his tendrils grabbed her by the leg and threw her into a wall. She was unprepared for the assault. She shakily got to her feet before seeing Nova standing in a fighting position.

"The Art of War, page 1... "All warfare is based on deception. Hence, when we can attack, we must appear unable; when using our forces, we must appear inactive"." Nova said as he attacked again with a tendril and slicing through several objects. That's when Shinobu noticed something about the tendrils that most would have missed.

"Is it made of the same materials of fingernails?" She asked herself aloud before hearing the demon talk.

"Yup, apparently, my claws can negate a demon's abilities to regenerate. I want to see if it's the nails that stop regeneration or if it's some kind of toxin my body produces." Shinobu smiled after hearing that, knowing that the demon was observant enough to try something new while using something old. It was working well.

"Alright..." Shinobu began to speak to herself, this time Nova couldn't hear her over his tendrils hitting the ground. "His tendrils have about a 50-meter range. They're fast and versatile... But I'm faster." In an instant, Shinobu sped through his defenses and delivered a powerful stab on his heart. Had it been her nichirin sword, he would have been killed from the poison.

He was sent flying through the air before running at Shinobu at full speed. His tendrils clashed against the bamboo sword multiple times at blinding speeds. At that moment, Shinobu took a deep breath in and jumped high into the sky.

"Insect Breathing: First form - Butterfly Dance Caprice." Nova's vision was flooded with the visual of a thousand butterflies passing by him. One fell behind, he lifted a finger for the insect to perch on. Without warning, he was sent flying once more in the direction of the other butterflies. "You're good and your tactical thinking is rather exquisite, but you simply lack the experience to match with those tactics. As of right now, you will learn to maximize your speed through breathing."

That last part confused Nova. He didn't know how the breathing would help, he was already doing it all the time. Although, he wasn't sure if he needed to.

"It's fundamental to all Demon Slayers. A basic, yet powerful technique. It is used in all breathing techniques and their variants. You will be learning Total Concentration Breathing." Nova was confused but wasn't going to question it. If there's magic then it would stand to reason that breathing could cause such a thing. He was resigned to his fate, but he would be lying if he said he wasn't a little excited. He'll be getting stronger... strong enough to kill a demon.

Author's Note

It's short, but I wanted to get to the point.