Dark Nuns — Ending Explained

In the film's climactic sequence, the canonical exorcism attempts led by Father Andrea fail to break the demon's grip on Hee-joon, leaving the child near cardiac collapse while Father Paolo's medical sedation proves entirely useless against the supernatural presence. Recognizing that institutional caution will cost the boy's life, Sister Yunia and Sister Mikaela lock themselves inside the makeshift sanctuary with industrial jugs of holy water and forbidden relics.

The ritual escalates into a brutal physical and psychological confrontation. The demon exploits Yunia's personal guilts and Mikaela's hidden anxieties, unleashing violent telekinetic destruction. To finalize the expulsion, Yunia takes the spirit's metaphysical burden into proximity with herself, executing a harrowing act of transference and sacrifice that drives the demon out of Hee-joon's body, successfully breaking the possession at the cost of Yunia's complete physical exhaustion and certain ecclesiastical banishment.

While primary readings highlight supernatural horror and feminist empowerment, psychological interpretations view Hee-joon's possession as an allegory for severe trauma and neurosis, where Father Paolo's clinical detachment fails because healing trauma demands profound empathetic immersion rather than antiseptic therapy. Another perspective reads the film as an institutional critique of post-colonial religious structures in South Korea, examining how rigid European ecclesiastical hierarchies clash with primal, urgent human survival instincts.