...during the era which demons started appearing because muzan kibutsuji was in search the blue spider lily flower .the doctor who was treating muzan before he was killed he had a patient who had an illness almost similar to Muzan but you got fully treated and became a demon who could walk in the sun and did not eat humans. he could he could evil demons into humans. during the sengoku era Muzan was fighting yoriichi he could sense a weird presence when he was fighting him he could not quite understand who it was but he felt his presence was very powerful. after escaping yoriichi, Muzan went to the infinity Castle where makima was sitting quietly. she had long black hair which cover the eye and a black kimono. after a few hundred years after Muzan encounter with yoriichi his wounds have healed completely. he sent upper moon 3 to look 4 the strange presence he felt that day. meanwhile a patient who became a demon was known as satori he lived a modest life with his son. in the day he will do most of the household chores because his wife had died while he was being treated at night he would help those people who were turned into demons back to human this continued for some time until akaza found him . opening speech marks Technic development destructive death compass needle Air type! Akaza shouted I was sent here by my master to capture you my Mazda has been looking for you for a very long time. the attack landed and made a hole in his chest. satori runaway because he did not want to fight akaza jumped in front of him and punched in the chest where he was attacked. well you leave me no choice I didn't want to fight you but you leave me with no other alternative satori said blood demon art ravenous pack (he creates fox spirits that attack the opponent) all the Fox spirits attacked him akaza . he was shocked to find that his power was almost as powerful as for muzan . obi belt eightfold serpentine tsunami (he creates 6 or 8 water serpent to attack the opponent). well well what do we have here daki said as she jumped on a house . how was he able to counter My attacks she said with an angry voice. there there sister at least you slashed his face then upper moon 6 gyutaro said . how lucky of you you can walk in the sun and you have an handsome face. I will cut you into pieces gyutaro Said in a menacing voice blood demon art blood sickle ahh! bend to my will. he attacked satori with it they were imbued with a deadly poison it had started 2 take effect and slowly weaken satori . the 3 demons where able to capture him and take him to the infinity Castle. but it was a trick in order for satori to find out who was there master. he wanted to know if their master was the one making humans into demons....

in the infinity Castle satori sat there staring blankly at the endless numbers of doors muzan Hussain was above him doing experiments to find a way 2 conquer the laughed maniacally as you said I finally found a demon who can conquer the sun. then muzan saw the kimono satori had muzan said your kimono remind me of a demon Slayer who I killed a few years ago. when satori heard these words they reminded him the day he found his son lying on the ground lifeless he looked at muzan with a smile. Finally I found the person who killed my son with rage in his eyes. he was ready to attack , he dashed towards him then out of nowhere upper moon 1 kokushibou appeared moon breathing first form dark moon evening Palace. well this is the first time I've seen a demon using a breathing technique. kokushibou was able to cut both my hands but in the process he sword broke kokushibou was shocked 4 he had never seen a demon with such thick skin. interesting satori Said his arms regenerated well it's my first time 4 my arms to be cut off all the other upper moons were ready 2 attack him. satori looked around he had never seen demons with such bloodlust. he sighed then upper moon 2 Douma Said oh my this demon thinks he can fight master. muzan told makima 2 Open a door to a room where he can't escape. then she played her biwa then a door opened under his feet before he fell in he used his blood demon art blade whirlwind which slashed everyone and cut the demon king at the solar plex. satori fell with a smile on his face then the door close the shut. his ability rendered most of the demons regenerative abilities almost useless. he is a very powerful demon but I wonder why he's helping humans kokushibou wondered. for hundreds of years muzan tried 2 get satori blood but it was pointless satori was able to counter muzan in everyway . Muzan was sure that if he kept satori he would escape and kill him and the other upper moons. so he let satori out of the infinity Castle. kokushibou asked why muzan let satori out he said that it's better for him to deal with the slayers and kill them than to keep him here and one day he will kill us. It had been hundreds of years since satori walked in sunlight he stretched his arms and was excited to see how the world had changed he wondered whether his village was still around but told himself that they would have migrated long ago but it would be still fun to find the descendants. he was walking through the forest then he found what are the forest that hard wisteria flowers even though the flowers can repel demons he was resistant to it. he observed from us a far a group of demon slayers who were going for their entrance exam.

...Interesting I have always heard that in order to become a demon slayer you have to go through a test satori said. Then one of them piqued his curiosity he seems to be really strong. Then the slayers went into the cave where they were to fight lower level demons. His name was Zuni Managua he was a thunder breather he was quite talented his master told him he should take pride in his talent. He was a kind-hearted person he always helped those in need and loved his family. Then he encountered a group of demons thunder breathing first form thunderclap and flash he was able to cut through their necks he was excited after this. After a while he meet with the hand demon, well what do we have here he said in a loud voice most of the slayers had been killed by him. Then a small girl entered the cave satori was conserved of the well-being of the girl. She had a presence almost similar to his he followed her. The demon was able to land a punch on Zuni, but he didn't back down then the demon noticed that the girl was coming closer to his location Zuni told his sister to go back, but it was already to late the demon took her as a hostage. Then he started to panic he told himself that he was able to cut his necks if l move fast enough. satori wanted to know how he would solve the situation. Even before he could formulate a plan the demon crushed her legs. She screamed in pain then the demon landed a furry of punches to the demon slayer he coughed up blood. Every time he would try to attack the demon he would use his sister as a shield then heard a sound similar to that of a demon he started to get nervous as he knew that he could not take two demons at once. Then he hears well you put up quite a fight let me help you the Zuni passed out. This type of demon isn't as powerful as a twelve kizuki but is strong well because you said you want to be killed l will do it myself. Blood demon art blade whirlwind he cut through the neck of the demon without breaking a sweat. The Zuni wakes up to find out that his sister is safe thank God you woke up satori said.zuni was shocked to find out that his wounds have been healed completely.He asked what did satori did to him in order to heal up quite quickly.l made you into a demon huh? Zuni stares at satori and seems he was not joking and also your sister is a demon.Then uzumi turned pale white when he heard those words.Dont worry you wouldn't need to eat humans or be afraid of the sun hera take some tea it helps me to calm down.After satori explained everything to him uzumi was able to understand that he could still live like a normal person without a problem....