Rui

Blood Demon Art: Thread Manipulation

As Lower Moon Five, Rui's Blood Demon Art generates spider-like threads far stronger than steel, which he uses to bind, decapitate, or puppeteer both victims and his 'family' of demons. When pushed to his limit against Tanjiro and the Hashira, he releases his true, awakened strength before Giyu and Shinobu finally kill him.

Rui appears as a pale young boy with wide, staring eyes and shaggy pale hair, dressed in simple, tattered clothing that belies his monstrous strength. His awakened form sheds his childlike guise for a larger, more overtly demonic silhouette wreathed in threads.

Rui is obsessed with the idea of family, having forcibly assembled unrelated demons into a fake 'family' on Mount Natagumo and demanding total obedience and affection from them under threat of death. He swings between clingy neediness and explosive rage whenever his fabricated family is threatened.