Animeverse Slayer!

Leo was fascinated by this new knowledge.

"So all the other components merge with the core and become a new element?"

The chief nodded and then shook his head, "Yes and no. The core element is given some new properties filling out it's imperfection."

Leo rubbed his chin, "That's interesting. So it's possible to create a perfect weapon."

The chief nodded, "Theoretically yes."

Leo's curiosity was aroused, "Can you explain, if it's not a problem."

The chief didn't hold back, "Smithing can be basically divided into three process, melting, mixing and tempering. Melting is where ores are broken down individually, they are heated to obtain liquid metal."

"Mixing is as it's name implies is to merge them together before pouring into a mold. Every lineage has there own methods for these two process."

"Tempering is striking the metal mix after it is taken out of the mold. Though this step is common among every lineage, it takes talent to create a good weapon."

"Nine strikes form a set. Each strike should be precise and powerful. If the strike is weak the bonding will be weak, if it's too strong it won't be spread evenly."

"A smith must be able to identify the minute detail with each strike, after the fifth set each additional strike would intrinsically change the weapon. The higher the set the stronger the weapon."

Leo was listening with great interest. Suddenly he thought of something, "What about Nine by Eight and Nine by Nine weapons, has anyone ever created one?"

The chief sighed, "A Nine by Eight sword was created by a chief centuries ago."

Leo asked with excitement, "And a Nine by Nine?"

The chief shook his head, "Regretfully no one has ever created a Nine by Nine sword."

Leo pondered for a bit, "Why? swordsmith village has been around for nearly a millennia, no one has ever created one before?"

Lined with regret in his voice the chief replied, "For centuries every talented smiths to come by tried to create one but always failed. After countless defeat we came to conclusion, the last set requires something more than just physical tempering."

Hm?

The chief saw the confusion in Leo and asked, "Haven't you ever wondered why your sword turned red?"

Leo nodded.

The chief didn't let him wait and replied, "When you first touched your sword it resonated with you spirit. A higher resonance means the weapons abilities are upgraded. This is why a nichirin sword change colour. However, any weapon beneath Nine by Eight lacks the ability for higher resonance with first touch."

Leo knew where he was going, "Higher resonance... a red sword? But I thought a tighter grip meant a red sword."

The chief slowly explained, "A tighter grip means the weapon is becoming a part of you, you won't let it go even when you are unconscious, isn't that a form of resonance?"

Leo couldn't help but agree, the chief continued, "Any weapon beneath Nine by Eight will require time and special circ.u.mstances to change colour, we call it a forced resonance. Such a sword will be lacking compared to a true resonated sword."

Leo was stunned, "If Nine by Eight can reach such heights then what about Nine by Nine?"

The chief continued, "This is why we believe the last set requires something more, a spirit."

Leo frowned, "Weapons can have spirit?"

The chief nodded, "Theoretically, yes."

Leo asked again, "What's special about a Nine by Nine weapon?"

The chief's voice contained a hint of longing, "A Nine by Nine sword is perfect, the bond between the tiniest element will be unbreakable, it's sharpness and strength will reach a new pinnacle. A most importantly it will never age."

Leo felt a jolt in his heart, "Not age?"

The chief nodded, his voice trembled from excitement, "Theory suggests that a weapon with spirit will never age, it will be immune to all withering elements of nature."

Leo's heartbeat quickened. A sword that never age? That's practically the dream of every swordsman. Though Leo's sword was Nine by Seven, he still needed to maintain it from time to time otherwise it's sharpness would go down.

Sabito and the rest didn't interrupt Leo when he was speaking with the chief or rather they weren't able to. But when they heard about the ultimate weapon their eyes glowed with excitement.

After a long discussion about some details with the chief Leo and the rest were shown to their lodging.

Before the chief left he said a few words to Leo, "Honourable Hashira, if you are interested in forging we are more than happy to arrange a time for you to witness a master forging."

...

The woods behind the swordsmith village.

"Is it safe?"

A man with horns on his head and a panicked expression on his face asked a large porcelain vessel infront of him.

"Relax. There are only two Hashiras here, we just need to avoid them and kill as many swordsmith as possible."

A shrill voice sounded from the vessel. A second later smoke rose from it and formed a demon with the body of smoke.

"Let's go."

...

Leo was soaking his body in a hot spring. The heat spread throughout his body, it invigorated his tired bones.

He turned his head and found Tanjiro speaking cheerfully towards a boy with long black hair.

This boy was Sanemi's younger brother, Genya.

Leo was surprised when he first met him, his spirit was that of a human but his physical body was slightly inclined towards a demons. He can eat demons and gain part of their abilities.

Sanemi kind of said some harsh words when he saw Genya. However as someone with a spirit sense Leo knew he didn't mean it. Sanemi was putting hard front because he didn't want his brother to die.

Leaning comfortably Leo said to Sanemi who was soaking beside him, "I can shake his spirit and carve out a path for him to train."

Sanemi glared at Leo, "He doesn't need your help. He is weak and he should stay away from battle, lest he becomes a burden."

Leo rolled his eyes, "Sanemi-san, you do know of my ability, so why bother lying."

Sanemi ignored him. Leo didn't know what to say and simply enjoyed his time.