Episode 30

Insult (侮辱) is the 30th episode of the Kimetsu no Yaiba TV anime series, and the 4th episode of its second season.

Synopsis
Tanjiro realizes he's in a dream and figures out that in order to wake up, he must cut his own neck. Meanwhile, Enmu’s accomplices have entered the unconscious realms of Tanjiro’s group to destroy their spirit cores but are growing impatient at their own failures.

Plot
As Tanjiro positions his Nichirin Sword at his neck, the boy in his realm of subconsciousness becomes guided by figments of his spirits. They lead him to the spiritual core but he becomes unwilling to destroy it. Tanjiro pushes the blade in and the realm of subconsciousness opens as he begins to awaken from his dream; the boy falls into the abyss but Tanjiro's spirit saves him. The girl tasked with Inosuke's dream becomes lost in his realm of subconsciousness, a dim and creepy cave; she is subsequently chased by an animalistic Inosuke. The boy tasked with Zenitsu is stuck in his realm of subconsciousness, a pitch black emptiness he gets lost in. He hears the clap of metal getting closer and see an angry Zenitsu, menacingly wielding a pair of garden shears. Angered at the "parasite" invading his dream, Zenitsu gives chase and shreds the boy's clothes.

Tanjiro finally slashes his throat and wakes up. He realizes Nezuko is safe but sees his fellow Demon Slayers still asleep, as well as the children tied to their wrist. He notices his own wrist with a burnt rope, giving off the scent of a demon. He remembers the punched ticket and smells it too, confirming they fell into a Blood Demon Art. Tanjiro tasks Nezuko with burning the ropes but he fails to awaken Zenitsu or Inosuke. Suddenly, he is attacked by the girl tasked with Kyojuro's dream, armed and trying to stab him with her awl. Angered at her chance at a dream ruined, she is joined by Zenitsu's and Inosuke's attempted killers; she notices the boy tasked with Tanjiro and urges him too, but he doesn't respond. Tanjiro knocks all his attackers unconscious but apologizes for denying them their dreams, as he sadly mentions he wanted to stay in his too. The remaining boy meets him and explains how his soul had saved him, thanking him as he regrets his willingness to hurt him to escape his illness. Tanjiro walks outside and becomes repulsed at the strong demonic scent in the wind; he climbs up and confront Enmu. Enmu is stunned at Tanjiro awakening from his dream, commenting he could have shown him one where his family dies or a dream where he meets his father still alive. Enmu mutters to himself about his joy of witnessing the pained faces of someone experiencing a nightmare, as well as noting the more complex process he used for this specific Blood Demon Art; with the tickets punched containing his blood, his victims would fall asleep quickly and the act unnoticed, but he becomes perplexed at how Tanjiro had managed to wake up. Angered at Enmu tampering with his family memories, Tanjiro confronts him for intruding into his soul. Enmu sees his Hanafuda earrings and becomes overjoyed that his target came to him, happy he can now claim more of Muzan's blood. Tanjiro uses Water Breathing, Tenth Form: Constant Flux and charges forward; Enmu responds with Blood Demon Art: Whispers of Forced Unconscious Hypnosis and hits him, forcing him to lose consciousness. Tanjiro suddenly awakens and attacks, forcing Enmu to dodge his slashes and using his Blood Demon Art continuously, Tanjiro regains consciousness each time, making Enmu realize that Tanjiro is continually committing suicide to awaken each time. Enmu forces Tanjiro into a dream once more, only to be a nightmare with his bloody family and resurrected father angered at him being the only survivor of the massacre. Instead of being afraid, Tanjiro becomes furious and declares they would never say that. He leaps into the air and decapitates Enmu with Constant Flux. Though he successfully decapitates Enmu, Tanjiro becomes concerned that killing him was too simple.

His suspicions prove correct when Enmu's head grows flesh and adheres to the Mugen train's carriage. Enmu mocks him for believing he had succeeded, as he happily mentions that while Tanjiro and the other Demon Slayers slept, he had fused with the entire train.

With the 200 passengers at his mercy, Enmu challenges Tanjiro to save them by himself from being devoured. Realizing he can only protect 2 cars in the least, Tanjiro begs his comrades to wake up. At that moment, Nezuko succeeds in waking Inosuke, who bursts from the roof reinvigorated and declares himself "Lord Inosuke". He jumps into the now fleshy, demonic train carriage and slices the pieces with Beast Breathing, Fifth Fang: Crazy Cutting.