Rui is the primary antagonist in the Mount Natagumo Arc of Demon Slayer: Kimetsu no Yaiba. Rui's Blood Demon Art is Thread Manipulation.
Enmu was the main antagonist in the Mugen Train Arc of Demon Slayer: Kimetsu no Yaiba. He was a demon affiliated with the Twelve Kizuki. Enmu's Blood Demon Art is Sleep Inducement.
Gyokko is obsessed with the artistic approach. He lives in a pot and switches to another one in no time, making him travel between places very fast, almost like teleporting.
This brother and sister pair live as one. Daki uses Flash manipulation, she can manipulate her flesh into a cloth sash. Gyutaro uses blood manipulation as his demon art.
Hantengu uses Emotion manifestation to kill his opponents. He can create multiple highly powerful clones, each representing an emotion, their own personality and abilities.
Nakime s the biwa player shown every time Muzan held a meeting. She uses infinity castle, which gives her total domination over the extra-dimensional fortress where she resides.
Doma uses extremely powerful cryokinesis, in which he can generate ice and frost from his flesh and blood and can spawn and manipulate anywhere in his surroundings.
Akaza uses martial arts such as destructive death, his demon art that contains shockwave-like attacks and his Soryu style, which he manipulates in any form, at any distance.
His blood art makes him manipulate the shape and range of his sword slashes while using his moon breathing. He could create blades with his flesh that can pop out of his body anytime.
Muzan is unrealistically powerful, with an incredible amount of speed and regeneration power. He could alter and control his flash, limbs, and even his organs. He had seven hearts and five brains inside his body.