Training

Demons are a race of immortal, supernatural, ancient and malevolent beings, and the enemies of the Slayer Corps, or that's what his ancestor had told Shin.

A year had gone by since the beginning of Shin's training.

For the past year, he had done nothing but train at night. At the beginning of his training his ancestor whose name he still didn't know of continued to make him descend the mountain every night constantly while being chased with the intent of severely hurting Shin if he slipped up.

After repeatedly descending the mountain, night after night, he slowly improved and memorized the layout of the mountain, he was less injured and covered in dirt each time thanks to his senses sharpening and trusting them more as well.

The constant running helped to build up his strength and stamina faster, with him being more proficient with using his senses better.

However, after a few nights of this his ancestor decided to bump up his training by changing his starting point from higher up the mountain and attacking more frequently to push him to his limits.

Like the first time he went through this, it was complete hell but like before he gained control of breathing and made it down the mountain successfully.

After half a year Shin was given a katana to run down the mountain with, it didn't take him long to realize with the addition of the sword that his movements were hampered significantly as he had to be aware of Its existence, basically, its length and weight, and how to hold it properly while running.

With the addition of the sword, he found himself getting cut more frequently from his relative's blade unable to escape its reach, though they were light cuts it meant he needed to focus more and improve.

In the midnights when he descended the mountain, he was to swing his katana over and over again until his arms felt like they would fall off.

"One thousand nine hundred and ninety-nine! Two thousand!" Shin yelled out, veins showed on his arms as he slashed for the last time while avoiding his teacher's attacks. As the name suggested Moon breathing mimics the Moon, specifically the shape of classical crescent moons, and replicates it with the user's movements.

He was to swing his sword as swiftly as he could and slash ahead of him in a crescent moon motion 2000 times while moving around to avoid being cut by his ancestor's sword, though the movements looked standard they carried a lot of power behind them.

"A thousand more!" The demon's voice yelled from the side of him while releasing another attack, Shin could only groan and force his already tired body to move.

While he trained he would usually question why demons never used umbrellas to block the sun but he decided to shrug it off.

Once day arrived, his relative would go into hiding and wouldn't show himself at all, Shin didn't seem to care about it as this had happened more than once over the time he was there, while his teacher was gone he'd usually train since he had nowhere to return to.

On some nights, instead of running down the mountain his ancestor would take him to an open field and train or instruct him on how to use a katana.

"Katanas break easily." he suddenly spoke.

Shin raised an eyebrow. 'Where did this come from?'

"Though it's strong vertically, it's weak horizontally, so you need to apply force straight along the blade." The six-eyed demon ignored Shin's question and unsheathed his sword, and in a flash, five trees were cut effortlessly.

Shin continued to stare at the trees, noticing how small lines formed on them as his ancestor continued to speak. "You and your blade are one, the direction of the blade and the direction in which you apply force must be exactly the same." He said before looking Shin directly in the eyes.

"Do you understand what I am saying? If you ever damage your blade, or in another term, break it, I will break one of your limbs" He sheathed his katana saying this and the trees from before all came crumbling down into diced pieces.

Shin's eyes widened and nodded his head.

___

After some time of following instructions and learning to fight without a sword, Shin stood in a clearing from earlier lifting his sword in position ahead of him with his relative in the opposite direction barehanded.

Shin stood there not doing anything other than looking into his relative's eyes until suddenly he found himself high up in the air upside down.

"Huh?" Shin muttered to himself as he began following to the ground head first.

Realizing his situation he quickly tried to stabilize himself in the air and flip himself back over to avoid hitting his head.

When he hit the ground his teacher flickered next to him and threw him up into the air once again like a toy.

The training session was to get him accustomed to being thrown around and recover from any position while defending himself.

After hours of this tor- *cough* training Shin finally collapsed from fatigue covered in bruises.

The night after, his teacher began to teach breathing techniques to the boy.

"Breathing Styles are swordsmanship forms practiced and taught by the Demon Slayer Corps. The Breathing Styles make use of specific and concentrated breath patterns, which increase the user's lung capacity and amount of oxygen in the blood."

"This increase of oxygen allows the user to enhance their physical abilities and mental concentration, allowing them to fight on par with Demons, whose physical prowess surpasses that of the average human." The demon spoke while drawing his sword then slashing swiftly in a single motion, numerous chaotic crescent blades originated from the slash carving up the earth beneath them.

"As I told you before total concentration breathing empowers the user, but it also has the power to help heal them faster as well"

Shin nodded his head taking everything in.

"Now relax your upper half while bracing your lower body," he instructed.

Shin followed the instructions and did as told, relaxing his upper body while bracing his lower half.

"Breathe."

Shin took a deep breath in *Sssss* and then exhaled *haaaa*, Shin was bout to do it once more but was hit hard with the butt of his teacher's sword.

"Wrong, do it again."

After hours of being hit and told he was doing it wrong he was finally successful and taken to an open field wider than the one before, his relative had told Shin to 'Become one with the moon'.

"What do you mean become one with the moon?"

Without saying anything his relative pushed him into the moonlight leaving him even more confused.

"Are you going crazy? Do I need to find a doctor?" Shin titled his head while asking this.

He couldn't really see his relative's face but he felt something hitting him in the back of his head and him going face first into the ground. "Train."

Shin stood back up with a groan and tried his best to figure out what becoming one with the moon exactly meant. 'Maybe it's that thing he did earlier while explaining breathing techniques?'

He gripped his blade and swiftly slashed forward with all his strength in the shape of a crescent moon, once the swing ended his arm felt somewhat sore but he continued to 'become one with the moon' under his mentor's gaze.