The Hashira, Sanemi and Iguro, along with their comrades head to an abandoned castle on top of a mountain for a mission, while Tanjiro is being treated at the Butterfly Mansion for the wounds he suffered at the Swordsmith Village. Later on, the Hashira gather at the Ubuyashiki Mansion to hold a Hashira meeting, where Muichiro reveals how the marks manifested. In an effort to strengthen the entire Demon Slayer Corps from the bottom up, the Hashira Training begins...
I hear it's called
"Infinite Slashing Training"...
سمعتُ أنّ تدريبه يُدعى
،"تدريب التّقطيع اللاّنهائيّ"
Mit seinen unerschöpflichen Übungsschlägen.
Den Namen kann man wörtlich nehmen.
Oí que se llama entrenamiento
de melé infinita. De seguro nunca acaba.
il aurait préparé
un affrontement continu,
Lui terrà l'allenamento 
dei colpi illimitati.
Eu soube que é o Treinamento 
dos Golpes Infinitos...
Он готовит бесконечную отработку атак.
И учтите, это не просто слова.