Demon Slayer: Seraph of Radiance

As Tanjiro began moving across the wooden posts, Kawanishi stepped back to stand beside Urokodaki, smiling. "What do you think? My little brother has a pretty good temperament, right?"

Urokodaki nodded, "Indeed. I thought he'd fall off right away."

Breathing techniques weren't as simple as ordinary breathing. In the beginning, merely activating the technique felt awkward and uncomfortable, making it difficult to maintain. The first hurdle was successful activation; after that came the challenge of maintaining it.

Maintaining required absolute mental focus on one's breathing, without distraction. Fear, anger, sorrow — these emotions must be suppressed in battle, as any strong fluctuation could interrupt the breathing technique, which would harm the body if broken abruptly.

Next came Total Concentration Breathing.

The user learned to fully control their breath, circulating and focusing energy wherever needed, massively enhancing their physical strength and allowing them to rival demons.

After mastering Total Concentration, there was the Constant state — maintaining Total Concentration at all times, even while eating, drinking, exercising, or sleeping. This state was the gateway to becoming a Hashira.

Unless one had reached Total Concentration, extreme emotional swings should be avoided.

Just now, when Urokodaki scolded him, Tanjiro's breathing instantly transitioned into Total Concentration.

Tanjiro had trained in Water Breathing for a month without reaching Total Concentration, yet with Fire Breathing, he achieved it in less than a night.

He might even surpass that legendary prodigy and break the record for becoming a Hashira the fastest in Demon Slayer Corps history.

Fortunately, Kawanishi had brought Fire Breathing to him in time. Had Tanjiro practiced Water Breathing too long, his physique would've adapted, making it harder to switch.

Tanjiro, you've already trained for a month — there's one month left. Can you surpass that genius? I'll be watching closely.

As time passed, Tanjiro's movements slowed, his sweat-soaked clothes clinging to him.

Carrying a boulder weighing dozens of pounds while maintaining balance on the narrow posts exhausted him rapidly.

With prolonged breathing technique activation, his lungs felt like they were being sliced by knives, and his body ached more and more.

Yet, he gritted his teeth and persisted, his eyes shining ever brighter.

Kawanishi watched his brother intently from the side, smiling.

At this point, Urokodaki finally spoke, "Tanjiro, come down."

"I can still continue, Master!" Tanjiro insisted.

Urokodaki shook his head, "I know. But continuing would injure your lungs, making recovery much harder."

"Too much is as bad as too little. Come down."

No matter how gifted, even lungs needed to gradually adapt to the breathing technique's intensity to build a foundation for the Constant state.

For now, he wasn't letting Tanjiro attempt Constant Breathing yet — he needed to fully solidify Total Concentration first.

Tanjiro finally jumped down, set the boulder aside, and walked over to Urokodaki and Kawanishi. His arms felt as heavy as mountains.

"Massage your arms," Urokodaki instructed. "If you let the muscles stiffen, you won't be able to train tomorrow."

"Yes, Master." Tanjiro struggled to lift his hands, massaging his sore muscles.

Kawanishi stepped up, "Here, let me help."

Before Tanjiro could refuse, Kawanishi grabbed his arms and massaged them forcefully.

After a while, Tanjiro felt better and could breathe more comfortably. Urokodaki asked, "How are you? Can you hold a sword steadily? Are your lungs better?"

Tanjiro nodded confidently, "Thanks to Brother, my arms have recovered quite a bit. I can hold a sword. My lungs just sting slightly; it's not serious."

"Will we be practicing sword forms now?"

Urokodaki shook his head, "No. You've mastered Water Breathing forms well enough. What you need is to fight with Fire Breathing and develop your own sword forms."

Water Breathing forms were derived from Water Breathing, but didn't suit Tanjiro anymore. Only Fire Breathing forms would let him wield full power.

Once someone had a breathing technique, sword forms naturally derived from it. Breathing was the foundation.

Given Tanjiro's solid foundation in forms and his talent, this wouldn't be difficult.

Urokodaki wanted Tanjiro to train while tired but not exhausted — the typical state of demon slayers in battle, as demons' regeneration kept fights grueling.

He walked over to the six practice swords Kawanishi had brought.

Kawanishi, sensing something was off, began to feel uneasy.

Urokodaki glanced at the curious Tanjiro, then at Kawanishi, who was subtly stepping back. With a gentle smile, he said, "Tanjiro, you'll be sparring against a demon."

"You performed well in the previous test, but you still need battle experience. And lucky for us, we have a demon right here."

He handed one of the swords to Tanjiro.

Tanjiro accepted it eagerly, looking at Kawanishi. "Brother, I know I'm not your match, but I still want to try."

Kawanishi laughed, "You rascal, I'll beat you black and blue."

But Urokodaki smiled mischievously. "Not necessarily. At full strength, you'd overwhelm Tanjiro — that wouldn't help him grow."

"Besides, this isn't just training for Tanjiro — it's training for you too."

Confused, Kawanishi asked, "So?"

Urokodaki pointed to the remaining five swords and said pitifully, "Why do you think I had you bring these?"

Kawanishi sucked in a sharp breath as a terrible thought struck him. "No way…"

"It's exactly that," Urokodaki confirmed. "These blades are to limit you. They'll be stabbed into your body to restrain your movement and give Tanjiro a chance to fight you."

"This will also be valuable training for you."

Tanjiro protested worriedly, "Master… maybe you should spar with me instead. It'll hurt Brother."

Though demons couldn't die easily, they still felt pain.

Yet, oddly enough, Kawanishi sensed a hint of expectation in Tanjiro's eyes.

Urokodaki explained sternly, "The Demon Slayer Corps fights demons. Sparring with me would only teach you how to fight humans."

"Demons and humans fight very differently. Sparring with your brother is far more useful."

Having a demon as a sparring partner was an incredibly rare opportunity.

Still confused, Kawanishi asked, "But what benefit is there for me?"

Urokodaki countered, "Can you ignore pain completely? Truly ignore it — no matter how severe, no matter if your brain is attacked?"

Kawanishi's expression darkened. He hated to admit it, but… "No."

Urokodaki spoke gravely, "You're a demon."

"I've seen demons split in half who could still leap and attack."

"I've seen demons fight on while laughing with holes in their brains."

"You've become a demon — don't waste that body. Even I must admit, demon physiology is incredibly strong."

Kawanishi fell silent. It was true — he couldn't do what Urokodaki described.

"So, what do I need to do?" he asked.

Urokodaki smiled kindly and unsheathed one of the practice blades with a metallic ring.

"One blade — through your brain."

"Four blades — one through each limb."

"Take this kind of damage repeatedly, get used to it — and you'll become stronger."

As Urokodaki approached with the gleaming blade, Kawanishi gulped.

Is it too late to run?

(End of Chapter)