Demon Slayer Episode 17 English Dubbed Episode Title:You Must Master a Single Thing.Episode Description:Zenitsu flees from a spider with a human head only to find the nest of the demon that made it, the elder son, whose venom turns humans into spiders. He reveals to Zenitsu he was bitten by one of his spiders and will lose his human form in thirty minutes. Zenitsu hides in a tree as other demon-spiders approach him. He remembers his days of training under Jigoro Kuwajima, who paid off his debt if he became his apprentice. He was struck by lightning while hiding from his training in a tree, which turned his hair yellow. He thinks to himself he is a pathetic person and wants to stop being such a coward...