Due to the absence of any provided film details, plot points, or character descriptions for 'Broken Coffin', an evaluation of its LGBTQ+ portrayal cannot be made. Therefore, the net impact is categorized as N/A.

Based on the information provided, no identifiable transsexual characters or themes are present in the film "{断魂刀} ({movie}, {1970})". Therefore, an evaluation of its portrayal is not applicable.

The movie does not contain any action or adventure elements.

The film is a direct sequel to 'El vampiro' (1957). Key characters from the previous installment, such as Marta, Enrique, and Count Lavud, retain their established genders and are portrayed by the same actors. No instances of gender swapping for established characters are identified.

No information about source material, prior adaptations, or historical figures is provided for the 1970 film "Broken Coffin." Therefore, it is not possible to identify any character whose race was canonically established prior to this film and subsequently changed.