Why Did Muzan Put All the Demon Slayers in Infinity Castle?

Currently anime Kimetsu no Yaiba has entered the final chapter in its story, namely the Infinity Castle Arc.

Before that, there was a moment where Muzan was cornered, but he opened a portal to Infinity Castle and let in not only Hashira to his castle, but all the active demon hunters.

Why did Muzan put all the active demon hunters in his castle?

1. Muzan is arrogant and wants to kill all active demon hunters in the same night.

doc. Ufotable/ Kimetsu no Yaiba Season 4 Hashira Training Arc

Muzan was already very annoyed with Ubuyashiki and all the demon hunters who interfered with his plans, plus his dream of being able to live under the sunlight again was getting closer because of Nezuko.

After Ubuyashiki’s death, Muzan wanted to make that night a momentum to finish off all active demon hunters. Therefore he put all active demon hunters into Infinity Castle.

Apart from being annoyed with them, Muzan’s goal was of course to kill the Ubuyashiki family, all the demon hunters, and be able to live under the sunlight again all at once, on the same night.

2. Muzan is confident that he will be successful in eliminating all the demon hunters because there are many demons in his castle, including the Upper Moon Demon.

doc. Ufotable/ Kimetsu no Yaiba Swordsmith Village Arc

Then why did Muzan confidently put in everything, not just Hashira Just? Yes, Muzan is basically arrogant, but he has reasons too.

He is confident that he can successfully kill all the demon hunters including Hashira because in the castle there are so many demons that the number is almost infinite.

The remaining Upper Moon Demons were also all in the castle, plus the castle in normal conditions would not be affected by sunlight (remember, in normal conditions), because of that Muzan was confident that he could make all the demon hunters exhausted and eventually die at the hands of the castle demons.

3. Muzan’s plan failed because the Hashira and other demon hunters were upset about Ubuyashiki’s death, plus there was the factor of Tamayo and Yushiro.

Tanjiro at Infinity Castle (doc. Ufotable/ Kimetsu no Yaiba Season 4 Hashira Training Arc)

Muzan somewhat miscalculated here because he underestimated the demon hunters, even though Ubuyashiki had warned that his death would not be in vain, but would be “fuel” for the other demon hunters to defeat Muzan.

The demon hunters, especially the Hashira, were present in a state of anger over Ubuyashiki’s death, plus they had been trained very hard by the Hashira.

One by one the Upper Moon Demons will be defeated by the demon hunters until finally only Muzan remains.

So what do you think, is Muzan’s decision right?