Black Butler includes explicit transgender representation via Grell Sutcliff and strong homoerotic undertones between male characters. However, Grell's identity is often played for comedic effect, and the subtextual relationships are not explicitly affirmed, leading to a portrayal that is present but neither strongly positive nor negative in its overall impact.

The anime features Grell Sutcliff, a Shinigami who uses feminine pronouns in Japanese and expresses a desire to be a woman. Grell's gender expression is integrated into their flamboyant, eccentric, and often villainous persona, contributing to both comedic and antagonistic elements. The series neither explicitly affirms nor denigrates trans identity, treating it as a characteristic rather than a central theme.

The show features Ran-Mao, who demonstrates skill in physical combat by defeating multiple male opponents in close-quarters engagements without relying on firearms or supernatural abilities.

The series frequently portrays Christian institutions and figures as corrupt, hypocritical, or manipulative, often using religious pretense to justify immoral actions. The narrative consistently questions divine justice and the efficacy of traditional faith in a world rife with suffering.