Rui is one of the strongest demons and a member of Twelve Kizuki in Demon Slayer: Kimetsu no Yaiba. He is the second Lower Rank Demon we see in the Manga and Anime.
Rui, before he was killed, held the position of Lower Moon Rank Five and belonged to the spider family in Demon Slayer. He is the primary antagonist of the Mount Natagumo Arc.
While fighting with Tanjiro and Nezuko on Mount Natagumo, he completely overwhelms them and gains the edge over everyone. Giyu Tomioka, the Water Hashira, destroys Rui’s web as he tries to kill Tanjiro with his Blood Demon Art: Murderous Eye Basket.
Rui attacks Giyu with Cutting Thread Rotation. He says that the Demon Slayers are a bunch of worthless lowlifes. Total Concentration is Giyu’s answer: Eleventh form of water breathing: Dead calm. Rui yells angrily that it doesn’t matter what the technique is if it destroys his own web of threads. Rui, who is shocked and confused, tries to make the attack again, but Giyu is gone by the time he blinks. A second later, Rui’s head is cut off.
He thinks back to when he was a weak boy, and Muzan turned him into a demon. He thinks about how his parents reacted when he killed someone and how he then killed them and remembers that after that, he wanted to feel something he used to feel, so he made the Spider Family feel like a family again, but it didn’t work.
In the afterlife, he is sad that his parents will never forgive him because he killed other people. The spirits of his parents then comfort him by telling him that’s not true and that they’ll always be with him and can join him. Suddenly, Rui starts to cry as he hugs them, and then he changes back into a human and asks for forgiveness as they make peace and enter the afterlife.
Rui was much stronger than other demons because he was able to easily take over and unite many demons of Mount Natagumo, making them work for him and become part of his family. His strength was shown again when he easily beat a skilled fighter like Tanjiro Kamado.
Also, demons powered by his blood were strong enough to kill dozens of Demon Slayers without much trouble. Rui’s power still wasn’t as strong as the Hashira’s, and Giyu Tomioka was able to easily beat his technique and then cut off his head with ease.
Rui’s body was very strong and hard to cut. It was much harder than that of lesser demons, as Tanjiro pointed out when he said that Rui’s skin was much harder than that of his “Father,” who could also fend off attacks from a Nichirin sword. He even says that his skin is much more durable than his threads. Rui’s neck is so strong that Tanjiro’s broken Nichirin Sword couldn’t even scratch it.
Infinite Strength: Like all demons, Rui had an unlimited amount of strength and endurance. He never got tired or hurt.
This was shown by the fact that he didn’t move at all when Nezuko Kamado scratched his face and made him bleed a lot. Rui didn’t show any signs of pain either when he cut off his own head or when Giyu cut off his head.
Rui had superhuman strength. He could easily beat Tanjiro by kicking and punching him, launching him into the air or a very long way away, and making him bleed with every blow.
Menacing Aura: Tanjiro said that Rui had an aura that made the air feel thick and heavy just by looking at it.
Rui was able to give other demons his power or even his appearance if they drank his blood.
The process was very painful for the demon, and even ripping off their face wasn’t enough to finish it. Once everything is done, the demon will look like Rui, with pale white skin and red markings. They can also sometimes get spider-like traits, like the Elder Brother Spider Demon and the Father Spider Demon. He can teach them his Blood Demon Art by giving them a spider that they must eat. If Rui was defeated before the rest of his “family,” the Blood Demon Arts he gave to other demons would not work.
Rui Blood Demon Art: Thread Manipulation
Rui’s Blood Demon Art let him make thin threads from his own cells that were hard to tell apart from string and move them in any way he wanted. He would usually move the threads with his fingers, like a puppeteer.
Rui was very good at using his threads in battle. He used the environment to make a barrage of string attacks or create unavoidable web techniques that caught his opponents and cut them into pieces.
Because Rui’s body is so strong, the threads he controls are also very strong and sharp. They can cut as well as Nichirin Swords and block their blows as well. Rui can make them even stronger and last longer by putting his blood into them, which gives them a blood-red colour.
Rui’s Blood Demon Art Techniques –
Cutting Thread Cage: Rui makes a string in the shape of a web that wraps around his opponent and cuts them into pieces.
Murderous Eye Basket: Rui wraps his threads around the target to make a sphere-shaped cage that keeps getting smaller until it cuts the target into pieces.
Cutting Thread Rotation: Rui makes a wheel of threads that spin and cut the opponent into pieces when it reaches them.
Rui was a young boy who was short and had a small body. His skin was very pale and white, and there were red dots all over his face. They were above his eyes where his eyebrows should be, below his left eyelid and up to the top of his nose, and along the length of his right cheek. He had light pink hair that looked like spider legs. His eyes’ whites were red, and his irises were a light blue.
He wore a white kimono that was too big for him and had spider webs on the sleeves and the bottom. The collar was loose and had the same dot-like markings as his face.
Rui has one of the most touching backstories in Demon Slayer: Kimetsu no Yaiba. After reading about it, it makes you feel bad for him for going through all he had.
Frequently Asked Questions
How old is Rui from Demon Slayer?
Rui is more than 30 years old chronologically, but only appears to be a before teenage boy at around 11-13 years old.
What Rank is Rui in Demon Slayer?
Rui was the Lower Moon Rank Five among the Twelve Kizuki. Even then, his strength was comparable to Lower Moon Rank One or Two.