The flashback also reveals that Yoriichi had a twin brother named Michikatsu Tsugikuni, who became a
Kokushibo (黑死牟) is the secondary antagonist of the manga/anime series Demon Slayer: Kimetsu no Yaiba. He is Upper Rank One of the Twelve Kizuki, and the archenemy of his younger twin brother, Yoriichi Tsugikuni.
1) Kokushibo
Being the older twin brother of the legendary Demon Slayer Yoriichi Tsugikuni, Kokushibo had considerable strength as a human. This impressed Muzan enough to give Kokushibo his blood and turn him into a demon and the first member of the Upper Moon Demons.
Is upper rank one Tanjiro's father? No, they are not related. Tanjiro, by PURE COINCIDENCE, heavily resembles Yoriichi Tsugikuni, the creator of Breath swordsmanship, the only other person to use Sun Breathing, and the only person Muzan ever feared.
Kokushibo, the upper moon rank 1 demon and Yoriichi are not Tanjiros' father and neither are Tanjiro's relatives. However, Kokushibo and Yoriichi are siblings and respect each other a lot despite Kokushibo hating the entirety of his brothers' being.
After the deaths of Daki and Gyutaro, Kaigaku was promoted to become Upper Moon Six of the Twelve Demon Moons due to his power and confronted Zenitsu as a rematch he always desired.
Many Kimetsu no Yaiba fans deduce that Yoriichi is Tanjiro's father, but that isn't the case. However, Yoriichi is responsible for teaching Tanjiro's ancestors the Hinokami Kagura, which has been passed down for generations.
Tanjiro's Current Demon Slayer Rank Is Kanoe
Murata, the Demon Slayer, who was almost digested on Mount Nagumo, is also a Kanoe.
The warrior Muzan feared was a swordsman named Yoriichi Tsugikuni. Yoriichi was the only slayer before Tanjiro who came close to killing Muzan, and the flashback of their fight occurred in Chapter 187.
The flashback also reveals that Yoriichi had a twin brother named Michikatsu Tsugikuni, who became a Demon Slayer but later turned into a demon and became Upper Moon One, Kokushibo.
We first see Doma when he is still the Upper Moon Six while he is in the middle of eating a geisha. Later he becomes even stronger and rises to the position of Upper Moon Two. He dies because of the lethal amount of poison he absorbed through Shinobu Kocho's body followed by Kanao Tsuyuri beheading him.
Fortunately, Zenitsu was able to single handedly beat the Upper Moon 6. Not only did he defeat the demon, he also created a seventh form called the Flaming Thunder God. These are the demons who have been given the title of Upper Moon 6 in Demon Slayer.
Nezuko is at least stronger than Daki, meaning that if Muzan could bring her back under his control, she would certainly qualify for the most prestigious title a demon can hold: a member of the Twelve Kizuki. Thanks to Nezuko's remarkable strength, she would have to be an Upper-Moon.
Or: Kamado Tanjiro unwillingly becomes Upper Moon Zero, and he willingly kills for Kibutsuji Muzan, because his sister unconditionally believes that the man saved them (and didn't kill their family), and thinks that they must protect him, and if Tanjiro disobeys, then his sister will be killed.
Shinobu Kocho is a capable Demon Slayer whose worthy of being the Insect Hashira. That being said, she's arguably the weakest Hashira when it comes to pure strength.
Yoriichi Tsugikuni, the first swordsmen to ever use Breathing Styles, once nearly killed Muzan with Sun-Breathing, and Muzan has been both physically and psychologically scarred ever since.
But if we are talking about the human form, then it's a big fat NO, because Tanjiro has just mastered the Sun Breathing whereas Yoriichi is the inventor of it, also he's way more powerful and holds an unfathomable battle intellect, larger than any Demon Slayer in history, so in conclusion, no one is remotely close to ...
In a nutshell, Muzan, being the progenitor of demons, is not scared of Doma. However, he is irritated by his inability to decipher Doma's thoughts and feelings, which is the ultimate control he has over all of his creations. Upper-Rank Two: Doma is a nihilistic maniac and a misanthropic cold-blooded demon.
Thus, Muzan created demons for hundreds of years even when he didn't want to turn someone. Since he didn't know anything about the Blue Spider Lily medicine, he needed others to find the plant for him by happenstance. This is the general reason why Muzan turned Nezuko into a demon.
Tanjiro decapitates Akaza with the Hinokami Kagura: Setting Sun Transformation. Akaza was bewildered, wondering how Tanjiro did not have any fighting spirit, comparing this feeling to fighting against a plant. He acknowledges that Tanjiro surpassed his speed.
Unfortunately, the answer to this question would be, no, he did not. Zenitsu, along with Tanjiro and Inosuke got way stronger than average corps members with training. In fact, he became one of the very few to even invent a new form of Thunder Breathing. However, his dream of becoming a Hashira was never realized.
Although Tanjiro remains at the fourth bottom of the hierarchy in the Demon Slayer Corps, he has always been strong enough to become a Hashira. Just the fact that Tanjiro has a fully developed permanent Demon Slayer Mark is a testament to his skills.
Devastated at what his brother had become, he cried, and Kokushibo could only show disgust that his younger brother was old but still alive despite having the mark. Yoriichi felt sorry for him, but knew he had to kill him and prepared to strike.
Though Tanjiro succeeds in making use of Water Breathing throughout the early parts of his adventure, he eventually discovers that he's better suited for Sun Breathing instead. Sun Breathing was the first Breathing Style utilized by Yoriichi Tsugikuni.
However, Tanjiro is not a descendant of Yoriichi Tsukiguni. Tanjiro is the descendant of someone who knew Yoriichi personally and was a good friend of his as well. Sumiyoshi was rescued by Yoriichi when a demon threatened his life. Since then Yoriichi often met him and they became close acquaintances.