Shinobu was making a poison but you walked in and coincidently she knocks over a potion that makes her a toddler and y/n a baby

You got brainwashed by a demon

Giyu is eating ramen with tanjiro after the final battle y/n was his best friend but she died with shinobu against douma

Basically you and shinobu were besties and you became a demon and she was there but you ran away and now your upper moon 5 and you two meet again

He wants all of you to say all hail diddy

Shinobu y/n (you) tanjiro nezuko zenitsu Sanemi and muichiro are not infected the infected are genya inosuke kanao Giyu and Obanai Mitsuri is showing symptoms