Demon Slayer is filled with demons of all sorts, and the ones that stand at their apex are usually the oldest and most dangerous. Due to the sheer amount of battle and survival experience they have amassed over the years and the number of victims that have been unfortunate enough to cross their paths, they have grown to be some of the strongest characters in the series.
These demons also have a wealth of knowledge that has been accumulated over centuries of existence. Here are some diverse stories behind the oldest demons in Demon Slayer, exploring their powers and their motivations.
10 Gyokko
- Age: 113+ years
He holds the rank of Upper Moon Five and is also one of the main antagonists of the Swordsmith Village arc. Gyokko is among the most powerful demons in the series, and his strength was evident in the fight against Muichiro, the Mist Hashira. If not for the latter awakening his demon slayer mark, Gyokko would have succeeded in killing him.
He can teleport through his ornate pots, control water, and summon demons that appear like fish. Gyokko has a twisted sense of affection for Kibutsuji Muzan, and it is evident from his joy of being decapitated by him. Muzan also rewards him by praising his artistry touting his ornate vases as some of the best he has ever seen in his long life.
9 Nakime
- Age: 113+ years
She occupied the rank of Upper Moon Four after Hantengu’s death left a vacancy. Her blood demon art gives her total control of the space inside the dimension that Muzan uses as his base, known as the Infinity Castle. She can open up portals to anywhere in the world from there and is the major means of transport the Upper Moon demons and Muzan use.
When she was a human, she was a biwa player who was mediocre till she discovered the trauma from a fresh kill enabled her fingers to play better. She then made it a habit to kill before every performance till she stumbled upon Muzan, who turned her into a demon.
8 Daki
- Age: 113+ years
Daki was introduced as an Oiran in the Entertainment District arc and was later thought to be the sole antagonist till the revelation of her brother Gyutaro; who together were the Upper Moon Six till their deaths at the hands of Tengen Uzui and Tanjiro. She was turned into a demon by the then Upper Moon Six named Doma to stop her from dying after being burnt alive by a samurai.
Her blood demon art enables her to control her obi sashes both in close and long ranges and even make them sentient. She and her brother have killed the most Hashiras of all the Upper Moon demons.
7 Gyutaro
- Age: 126+ years
He was born in the scummiest part of the Entertainment District, and because he was ugly, he wasn’t favored by people like his younger sister Daki. After coming back from his job as a debt collector, he finds his sister burnt alive. He kills the samurai responsible and proceeded to seek help for her till he stumbles upon Doma, who turned them both into demons.
His blood demon art allows him to send poisoned slashes of blood through the air in the form of waves. He is the stronger of the two siblings as he turned out to be more difficult to kill.
6 Akaza
- Age: 133+ years
Akaza was born to a poor and ailing man, so he had to resort to stealing to cater to the sick man. After being banished for his crimes, he was picked up by a dojo owner who trained him to become a master, and after, offered his daughter’s hand to him. After the deaths of his master and his wife at the hands of a rival dojo, he killed all those responsible and was later turned into a demon by Muzan.
Unlike the rest of the Upper Moon Demons, Akaza does not employ the use of weapons and relies on his immense physical abilities and martial arts techniques, which his Blood Demon art greatly augments.
5 Doma
- Age: 133+
He was once the Upper Moon Six and was responsible for displacing Akaza from the rank of Upper Moon Two. He is narcissistic and psychotic and has a god complex. He had his own cult, which comprised mostly women, and guess what? Young women are his favorite type of food.
His skill in Tessenjutsu, or the use of war fans in combat, surpasses Akaza’s martial arts techniques, and it works very well in combination with his blood demon art called cryokinesis, which allows him to create ice and generate very deadly gusts of cold wind.
4 Hantengu
- Age: 200+ years
Hantengu was a human born during the Edo era, he was a thieving murderer and also a liar. He spent the majority of his time moving from town to town, marrying women, having kids, and killing them all once the cat that represents his terrible nature gets let out of the bag.
He is capable of producing clones when he is decapitated, with his head and body splitting into two separate clones, and the clones will never die as long as his main body remains unharmed. His clones are also a manifestation of the emotions he has experienced in his lifetime.
3 Kokushibo
- Age: 480+ years
A demon that was once a demon slayer is a sight for sore eyes as most of them die honorably in the line of duty. Kokushibo is the twin brother of Yoriichi, the originator of Sun breathing. After activating his demon slayer mark, which gave him immense power and perception, he became a demon to prevent a curse that kills everyone with the said mark at the age of 25. He turned to Muzan, who ordered him to wipe out the demon slayer corps after his transformation.
He derived Moon breathing from the Sun breathing, just like every other breathing technique invented. He uses a weapon made out of his flesh and blood and can make it grow extra blades at will, making him extremely formidable in battle.
2 Tamayo
- Age: 500+ years
Before Tamayo became a demon, she was a doctor who developed a life-threatening illness. After meeting Muzan, he promised to “help her”, but of course, he turned her into a demon. She killed all her family members shortly after, and after wallowing in the grief and despair of what she had done, she swore to herself that she’d never lose control again.
She found a way to break away from Muzan’s control when he was severely weakened from his fight against Yoriichi and resents him wholeheartedly for turning her into a demon. She also came up with an antidote for turning demons back into humans through years of study and experimentation.
1 Muzan Kibutsuji
- Age: 10,000+
Muzan was born in the Heian Era of Japan; however, due to his sickness and projected low life span, he became subject to constant treatment. After ingesting an incomplete cure made from the Blue Spider Lily, he got better physically but discovered he could not walk in the sun, and he desired human flesh, therefore, becoming the first demon. He began looking for a way to complete the cure so he would be able to walk in the sun.
He was able to turn other people into demons by giving them their blood and creating a group of powerful demons called the Twelve Moons to serve him. The amount of his blood each demon has in them usually determines how strong they are, hence the rankings.