The artwork appears to convey a sense of depression. While I did not particularly enjoy the fifth episode, listening to the song "Revenge" by Xten gradually changed my perception and I began to fall in love with episode 5.
The music effectively captures the emotions of the episode, particularly the depressed state of the character Battler. The music sounds like a melancholic and hopeless individual expressing their feelings through song.
Without the music, I might have considered dropping the series because I struggled to connect with Battler's emotions.