Season 4 of demon slayer set up the final battle against muzan and upper moons, marking the beginning of the endgame.
To the hashira training shows the living hashira coming together to train the young demon slayers in order to prepare them for the final fight against muzan.
Webthe hashira training arc is the tenth story arc in the demon slayer manga and follows tanjiro training with the hashira for the final fight against muzan.