Due to the complete lack of available plot summaries or character details, an assessment of the film's portrayal of LGBTQ+ characters and themes cannot be made. There is insufficient information to determine if such elements are present or how they might be depicted.

Based on the limited information provided, there are no identifiable transgender characters or themes present in 'Mercy, 2021'. Without further plot details or character descriptions, a specific assessment of portrayal cannot be made, leading to a classification of N/A due to the absence of relevant content.

The movie does not contain any action or adventure elements.

Without information on the film's source material, plot, or character origins, it is impossible to determine if any character was canonically established as one gender and then portrayed as another.

There is no information provided regarding source material, prior adaptations, or historical figures for 'Mercy, 2021.' Without a baseline for character race, it is impossible to determine if any race swaps occurred.