The demon, now empowered with a burst of strength, suddenly appeared in front of Tanjiro, launching a powerful attack that Tanjiro blocked with his sword.
"That strength of yours... I want it," the demon said with a sinister smile before attacking Tanjiro repeatedly, targeting his head, liver, solar plexus, arms, legs, and any vulnerable area.
Tanjiro dodged and blocked the demon's attacks with his sword, knowing that his flesh alone couldn't withstand the demon's newfound strength. Despite his recent upgrades, Tanjiro found that the demon's power was a near mirror image of his own, making it nearly impossible to block with just his body.
As they fought, Tanjiro's mind worked in overdrive, searching for openings, exploiting weaknesses, predicting ten moves ahead, and maintaining the pace of the relentless attacks. He was also focused on developing a new form for his breathing styles.
Over the past ten days, Tanjiro had acquired knowledge of every breathing style except for Mist, Serpent, Beast, Love, Sound, and Moon Breathing. These six styles were unique to their respective creators, who were not present during the Final Selection. Thus, Tanjiro was unable to acquire their knowledge.
Tanjiro's mind drifted back to his time as Amon, watching the *Demon Slayer* anime and reading the manga. He vividly recalled each breathing style and began to learn Mist, Serpent, Beast, Love, and Moon Breathing while fighting the demon who called himself Muzan.
Although Tanjiro understood the forms of these breathing styles, he lacked knowledge of their specific breathing patterns. He could only experiment during combat, a risky endeavor that could potentially lead to serious physical harm from overexertion.
While experimenting with Love Breathing, created by Mitsuri Kanroji, Tanjiro felt a vague sense of danger due to his Hyper Cognitive Mastery(HCM). Kanroji's Love Breathing was known for its inhumane strength, so Tanjiro decided to focus on replicating it first. He continuously adjusted his breathing techniques based on the situation, aiming to mirror Kanroji's style.
Understanding that Love Breathing was derived from Flame Breathing to match Kanroji's incredible strength and flexibility, Tanjiro used his knowledge from the anime and manga to adapt Flame Breathing techniques to his own formidable strength, just as Kanroji had done.
Instead of replicating Kanroji's Love Breathing exactly, Tanjiro created a new breathing style that was similar but stronger and more efficient. He successfully developed a unique version of Love Breathing based on the forms he knew.
With this breakthrough, he moved on to create Mist and Serpent Breathing. Mist Breathing, derived from Water Breathing, focuses on disrupting opponents' senses, while Serpent Breathing emphasizes slithering motions and rapid strikes, adapting to the user's movements and techniques.
Tanjiro found Mist and Serpent Breathing easier to replicate compared to Love Breathing due to his extensive knowledge of Water Breathing and the lasting impression these styles left on him. He had a deep sympathy for their creators, Muichiro Tokito and Obanai Iguro, due to their tragic backgrounds and suffering. Muichiro, in particular, had died young while struggling to survive after his family was wiped out and he had to live in his brother's shadow. This personal connection made Tanjiro more determined to honor their legacies by mastering their techniques.
Obanai Iguro's tragic past was marked by severe trauma, having been used as a tool and a sacrifice from birth to resemble the demon snake. His mouth was painfully altered to match the demon's, causing deep psychological scars.
During the fight, Tanjiro created Mist, Serpent, and Love Breathing styles in just five minutes. The relative ease of mastering these styles, combined with his Hyper-Cognitive Mastery (HCM) and existing knowledge, made the process quick for him.
Had he not been forced to develop these styles mid-combat, Tanjiro would have taken more time to explore and perfect them. Unfortunately, he couldn't afford to delay, as the demon he faced was far stronger than anything in this world.
The battle caused widespread destruction within the infinite castle, with numerous rooms and doors being obliterated. This "Muzan" retained the original Muzan's control after devouring him, allowing him to command all demons.
Tanjiro and Muzan exchanged fierce blows throughout their fight. At one point, Muzan conjured a sword, leading to an intense sword fight. Each clash of their weapons generated shockwaves, causing further destruction as rooms were blown apart.
"You are quite strong. Who created you?" Tanjiro asked, fending off multiple tentacles that emerged from Muzan's back using his sword domain.
"Who created me?" Muzan echoed, caught off guard by the question.
He was born just three years ago, or rather, he regained consciousness and immediately received a mission from a voice in his head. The voice instructed him to find and destroy Tanjiro with all his might, promising absolute freedom in return—a freedom he didn't fully understand but deeply desired.
Throughout his mission, Muzan was granted the power to devour anyone and anything, acquiring their abilities and strength. Although he had only been "born" three years ago, his devouring skill quickly elevated him to a formidable demon capable of killing anyone.
Over time, he continued to hunt relentlessly, initially struggling against demons but gradually growing stronger through his accumulated power. His persistence led him to eventually defeat and consume other demons, further enhancing his abilities.
Muzan, having obtained the strength of other demons and the ability to regenerate almost instantly, spent the past three years focusing on hunting and killing demons. He ignored humans entirely, seeing them as irrelevant compared to the rapid strength gain he achieved by slaying demons.
Eventually, Muzan sought a new way to alleviate his boredom and turned his attention to the Demon Slayers. These humans, equipped with Breathing Styles, could challenge demons effectively. Intrigued by their abilities, Muzan began devouring Demon Slayers to acquire their techniques. This newfound power made him more aggressive, and he expanded his killing spree to both demons and Demon Slayers, showing no mercy.
One notable encounter was with a demon named Douma, who possessed an unusual ability to generate and control ice. Despite Douma's weakness compared to Muzan, his ice powers presented a unique challenge that Muzan preferred not to face again. Using his superior strength and speed, Muzan swiftly defeated Douma and devoured him, adding the ice abilities to his own arsenal.
Muzan also encountered a demon with six eyes and a sword, who was stronger than most demons he had faced. Despite this, Muzan overwhelmed him with his superior strength and speed, ultimately devouring him. This demon was notable for using a breathing style and had a distinctive mark on his face that seemed to enhance his power—something Muzan had never seen before in a demon and likely never would again.
From this encounter, Muzan acquired new abilities, including the Demon Slayer Mark and the Transparent World, which further enhanced his capabilities. He continued to explore and seek new challenges until he came across Mount Fujikasane. Utilizing an ability he had gained from another demon—the power of instantaneous teleportation—Muzan could quickly appear at any location. This teleportation ability, while originally limited in range, became a significant asset in his hands, allowing him to effortlessly pursue his targets by appearing right in front of them.
By devouring his prey, Muzan obtained their memories, which enabled him to locate and teleport directly to Muzan. After defeating and consuming Muzan, Muzan inherited his Blood Demon Art and the power to create demons of his own. This transformation solidified his status as the progenitor of all demons, further amplifying his already formidable strength and abilities.