Castlevania: Nocturne offers a largely positive and affirming portrayal of LGBTQ+ characters and themes. It features openly gay and bisexual characters whose relationships are depicted with depth and without stereotypes. The show integrates queer identities into its world-building, exploring themes of oppression and self-expression with dignity and emotional realism, moving beyond tokenism.

Annette, a character from the Castlevania game series, was originally depicted with a white/European appearance. In Castlevania: Nocturne, she is portrayed by a Black actress, which constitutes a race swap according to the provided definition.

The film consistently portrays Christianity, its Church, and its adherents as oppressive, flawed, and sometimes villainous. The narrative critiques the religion itself, often contrasting it unfavorably with pagan beliefs.