The nature seems be the main virtue of this film. Far to be a bad one, it seems too ambitious, reuniting, mixing different themes in eccentric manner, offering a ball of cliches and eccentric fantasies, suggesting improvisation and exploring, in not the most smart manner, old cliches, from Narcisse to Saint Sebastian significance in gay sub culture.
Sure, beautiful details, nice references to classic stories, not uninspired - forced in few scenes - links between erotic and horror. And, no doubts, interesting work of Tania Kontoyanni, not bad try to define his characters - and the seductive body - of Felix Antoine Duval.
So, I admitt, it is not fair or easy to be very critic about this film for me. Sure, not perfect, not brilliant acting but, as admirer of Gothic culture - the thoughts about The Monk by Matthew Gregory Lewis are the first- , Saint Narcisse is more than decent.