Kimetsu no Yaiba Episode 21 English Subbed Episode Title:Against Corps Rules.Episode Description:As Rui dies, he is finally able to remember his human life. He was born with a frail body, rendering him bedridden - until Kibutsuji turned him into a demon, giving him a strong body. His father then tried to kill him while his mother did nothing, so Rui slew them both, angry as parents were supposed to protect their children. His mother's last words were that she was sorry she couldn't give Rui a strong body, and his father had intended to commit suicide after killing him. He realizes too late it was a genuine bond after all. Kibutsuji returned and told him it was his parents' fault for not accepting him and Rui accepted that rather than the truth...