Ep 22. Master of the Mansion

Tanjiro and his companions finally reach the Infinity Castle - where Muzan Kibutsuji, the Demon responsible for the destruction of Tanjiro's family, may be hiding - and are immediately faced with a challenge: they must navigate the labyrinthine fortress and overcome its many traps in order to get to Muzan.

The group splits up, with Tanjiro, Inosuke, and Zenitsu going one way and Nezuko staying with their allies, the Hashira. The trio encounters a series of obstacles in their section of the castle, including a room filled with poisonous gas that threatens to suffocate them, a series of illusory rooms that disorient their senses, and a massive, towering demon that seems invincible.

Meanwhile, Nezuko and the Hashira encounter a powerful Demon that has taken control of the mansion's previous master. The Demon has the ability to manipulate the souls of anyone it comes into contact with, and it uses this power to try and sway Nezuko to its side. However, the Hashira stand firm and fight against the Demon, ultimately forcing it to retreat.

As the group makes their way deeper into the castle, they eventually encounter one of the Twelve Kizuki - the upper echelon of Muzan's Demon army. This Kizuki, however, is different from the others. Unlike the savage, bloodthirsty demons they've faced before, this one appears to be a refined, aristocratic gentleman. He welcomes the group to the castle and invites them to sit down for tea.

At first, the group is wary of the Kizuki's hospitality and rightly so - it soon becomes clear that this Demon is not to be trusted. He reveals that he has the ability to control the space around him, warping reality and controlling the dimensions of the room they're in. He toys with the group, showing off his powers and gradually wearing them down.

However, they soon learn that the Kizuki is not invincible. The Hashira, who has arrived to help after defeating the Demon who possessed the mansion's previous master, quickly figures out the Kizuki's power and comes up with a plan to defeat him. Even Nezuko, who had been under the Kizuki's spell, manages to break free and help in the fight.

The resulting battle is intense and brutal, with the Kizuki using his powers to try and gain the upper hand. But the group refuses to back down, fighting with every ounce of strength they have. In the end, they manage to overcome the Kizuki and deal him a fatal blow.

The episode ends with the group battered and exhausted, but victorious. They finally reach the top of the Infinity Castle, where they hope to find Muzan and put an end to his reign of terror. However, they're also aware that their foe is incredibly powerful and dangerous, and they'll need to be at the top of their game if they hope to defeat him.