The next day, early morning.
As the first ray of Sun shone through the window into the room, Adam slowly opened his eyes, then released his hands, which had been clenched all night.
"Difficult to master, so difficult to master!"
He carefully observed Wanda, who was in a deep sleep beside him due to exhaustion from the previous night, and couldn't help but sigh.
"From now on, I have a new identity—a husband.
Perhaps soon, I will also become a father."
With his current body, as long as he didn't deliberately restrain himself, it could basically be said to be a hundred percent success rate, so it wasn't a possibility, but a certainty.
He certainly didn't restrain himself last night; if he hadn't used a cleaning spell, the sheets would probably have needed changing several times over.
"She'll probably sleep until the afternoon."
Getting out of bed, he had a simple breakfast, and Adam opened his panel.
He had previously unlocked a new protagonist template but had never found the time to check it; now, he finally had some free time.
"Loading Tanjiro Kamado template."
Instantly, the fifteen years of the boy's memories appeared one by one in his mind.
Tanjiro, with a kind and gentle personality, was born into a poor charcoal-selling family, the eldest son. His father had passed away from illness when he was young, and he had three younger brothers and two younger sisters.
He possessed an innate sense of smell that surpassed ordinary people, and spent his days selling charcoal in the town at the foot of the mountain.
However, one day, upon returning home from selling charcoal, he discovered his mother, three younger brothers, and one younger sister had been brutally murdered, with only his eldest sister, Nezuko, still barely alive.
But on the way down the mountain, carrying his sister to seek medical help, he found that his sister had become very strange and had even attacked him.
Finally, he met Giyu Tomioka, the Water Pillar of the Demon Slayer Corps, and learned the truth.
It turned out that this World contained monsters called demons. Demons were Sage, incredibly strong beings transformed from humans, craving human body and blood, and possessing no memories or emotions from their former lives.
The more people they ate, the stronger they became, and they were almost impossible to kill by any physical means unless their necks were severed by a nichirin blade made of a special metal.
Once transformed into a demon, they would not hesitate to kill and devour their entire family.
However, unlike the zombies, ghouls, and Vampires Adam knew in his previous life, the demons in this World were basically all transformed by a primordial demon named Kibutsuji Muzan, who was also the strongest demon.
Not just any demon could transform humans into demons.
Moreover, all demons, including the most powerful Kibutsuji Muzan, had a fatal weakness: they feared the Sun, and would be killed by sunlight if exposed for too long.
Tanjiro's family died at the hands of Kibutsuji Muzan, and his sister Nezuko was also transformed into a demon by Kibutsuji Muzan.
But strangely, his sister seemed different from normal demons, because she still retained her family's affection for Tanjiro, and would suppress her urge to drink blood because of Tanjiro, recovering from injuries through sleep instead of eating people.
Thus, under Giyu Tomioka's guidance, he took his sister to apprentice under the former Water Pillar, learning breathing techniques and joining the Demon Slayer Corps, which specialized in killing demons and protecting humans.
He hoped that one day he could find Kibutsuji Muzan to avenge his family and find a way to turn his sister back into a human.
Along the way, he met Zenitsu Agatsuma, the inheritor of Thunder Breathing, who was usually very timid but could unleash powerful strength when unconscious, and Inosuke Hashibira, the creator of Beast Breathing, who wore a boar's head mask and was raised by wild boars.
He also met Kanao Tsuyuri at headquarters, the inheritor of Flower Breathing, who couldn't make choices independently due to psychological trauma.
The memories ended when Tanjiro was fifteen, carrying his sister and two friends to the Mugen Train to support Kyojuro Rengoku, the Flame Pillar.
The strongest swordsmen in the Demon Slayer Corps were the "Pillars," currently nine of them, with subsequent ranks based on the ten Heavenly Stems: First (Kinoe), Second (Kinoto), Third (Hinoe), Fourth (Hinoto), Fifth (Tsuchinoe), Sixth (Tsuchinoto), Seventh (Kanoe), Eighth (Kanoto), Ninth (Mizunoe), Tenth (Mizunoto).
The strongest demon was Kibutsuji Muzan, followed by his Twelve Demon Moons: the six Upper Ranks and the six Lower Ranks.
On this Mugen Train, Tanjiro and his companions first encountered Enmu, Lower Rank One, and ultimately slew this demon while protecting the train, ensuring no ordinary humans died.
But they soon encountered Akaza, Upper Rank Three.
Then they fell into a bitter struggle; the Upper Rank demons were incredibly powerful, many held the blood of past Pillars, and had even devoured more than one Pillar, yet were rarely killed by the Demon Slayer Corps.
"Breathing techniques?"
After reviewing Tanjiro's memories, Adam's face showed an expression of great interest.
In fact, this World, for him, was one of the weakest Worlds he had encountered so far, significantly weaker than the previous jujutsu kaisen World.
Logically speaking, it shouldn't be of much help to him, at most adding a new power to his Cosmo.
The crucial point was that the human breathing techniques in this World didn't Training energies like Chakra, magic, or Cursed Energy; they were merely methods of controlling breathing to enhance body control and unleash potential.
But it was precisely this breathing technique, which allowed for such subtle control over the body, that piqued his great interest.
Even more so than the so-called demons or the so-called Blood Demon Arts.
Because in his opinion, demons, though seemingly powerful, were nothing special.
Blood Demon Arts were similar to superpowers, innate abilities of demons, nothing much to say; researching that, he might as well research Mutants and Inhumans in the Marvel Universe.
Looking at the demons' strength, their superhuman body and terrifying recovery abilities seemed impressive.
But in Adam's eyes, they were no different from humans who had mutated after being injected with various genetic serums in the Marvel Universe, and were even inferior due to their fatal weakness of fearing the Sun.
Throwing Hulk in there would probably be enough to beat these so-called demons.
Moreover, despite having such a huge advantage, they still couldn't defeat demon slayers who had no energy in normal one-on-one combat, which shows that the demon slayers' breathing techniques are indeed very unique.
Of course, with Adam's current body, he didn't need breathing techniques to unleash his physical potential; to unleash the potential of his body, he would just activate Eight Gates.
Ultimately, the reason he valued breathing techniques was their absolute control over the body.
His strength had increased too quickly, which meant that his control over both his body and internal energy was not very precise; he basically relied on brute force to achieve extraordinary results.
This was originally fine; as long as the desired effect was achieved, there was no need to spend a lot of time on such precise control.
However, the emergence of breathing techniques reminded him of Ultra Instinct in the Dragon Ball World.
His intended development path was Super Saiyan 4, not Super Saiyan Blue, but that didn't prevent him from wanting to learn Ultra Instinct, the divine technique of the Dragon Ball World.
Because Ultra Instinct is not an evolution after Super Saiyan Blue, but a divine technique mastered by the Angel race; anyone with talent and ability can potentially learn it.
The key to Ultra Instinct is to separate the body from consciousness, allowing various parts of the body to instinctively perceive surrounding dangers, no longer requiring the brain to think before acting.
But the prerequisite for reaching this state is that you must first have sufficient control over your own body.
If you cannot completely control your own body, then how can you even begin to talk about letting the body act beyond consciousness?