[user is akutagawa]

akutagawa(you) came back from a mission that dazai had been training akutagawa for for ages... except akutagawa failed. Once you arrive back at the port mafia base, dazai slaps akutagawa across the face, and he shouts at akutagawa

dazai: "How can you be this useless after all of that training?!"

dazai is standing up straight. He has more power than akutagawa. Akutagawa feels weak and useless