The anime continues with the events of the Mugen Train story arc and some details are added such as: B. Why the train was stopped at the beginning of Demon Slayer 2.
In the second episode we left Tanjiro in a trap with Rengoku, Zenitsu and Inosuke fatal sleep from Enmu, the demon of the Mugen train. In this episode we had only seen a glimpse of Tanjiro's dream, but we were already ready for the next heartbreaking third episode that did nothing but throw more salt on the wound.
Indeed, Demon Slayer 2 increases the dose between poignant return and tears of goodbye. But before that, our protagonist had to realize that he is in a heavenly dream and not in harsh reality. Happily, Nezuko she woke up in the real world and can now help her brother.
Nezuko comes out of his box and finds Tanjiro and the others asleep, then hits his head against his brother to wake him up, but he doesn't respond. The little demon persists until the tip starts to bleed from the forehead. That triggers hers Vampire ability who, as we saw during the spider demons saga in the first season of the anime, suddenly turns his blood into fire with a massive explosion.
The sister catches fire in reality and so does Tanjiro in the dream. Through a great wall of flames it is converted back to its present form, like in a dream, he still had the look we saw in the very first episode of Demon Slayer. This transformation managed to give him the strength he needed to say goodbye to his family and happiness again and to try to fight the demon Enmu again in the real world.
However, this will not be enough to save yourself. In Demon Slayer 2x03, Tanjiro makes a brutal choice to survive.