This episode serves as a heavy, emotional finale to the series' most ambitious storyline. Unlike previous seasons, it shifts focus from comedy to the genuine consequences of Keima’s actions.
: Keima successfully awakens the final Goddess, Mercury, within Ayumi. The World God Only Knows Episode 12
: This marks the first time in the entire series that Keima is shown genuinely crying. On the rooftops, he apologizes to Chihiro in a moment of vulnerability, realizing the pain his "conquering" methods caused her. This episode serves as a heavy, emotional finale
If you were looking for the other finales, they vary significantly in tone: This episode serves as a heavy