I was very surprised and interested at the announcement that Elodie Yung had been cast to play Elektra in the TV adaptation of Daredevil. A canonically Greek assassin was to be played by a mixed race French/Cambodian. Elodie was certainly an immensely qualified actresses: a martial arts practitioner who had already been the star of a French police procedural and a drama degree from London, she was the type of person you would want to consider for a major action role in a serious series. As it turned out Elodie Yung did a masterful job as Elektra. I have no complaints, but it offers us something very important a successful and seamless race neutral casting decision.
As someone who has been involved in a lot of fan-casting discussions I know that people can get very rigid about the ethnicity of actors offered for a role. Sometimes that is called for (Ridley Scott’s Exodus Gods and Kings). Other times it seems a little out there, like all the criticism about Idris Elba playing Heimdall in Thor, since Marvel’s Asgard is a sword-and-planet fantasy world, not a true Norse setting.
The story, of course, in Daredevil is that Elektra is not adopted and therefore is of unknown ethnicity, but that’s a spoiler and when presented we have no reason to doubt that she is in fact Greek. Elodie can certainly pass as a Greek. That is how race neutral casting should work. There is no reason for the character to be any ethnicity but we clearly accept them for the ethnicity they are. The story makes it believable. Elektra could still be Greek, she could be French we have no idea and we accept it.
In Nolanverse Batman we get something very similar with Ra’s Al Ghul. Liam Neeson originally presents Henri Ducard while an Asian man is presented as Ra’s. In the end we know that Neeson is Ra’s and the double was theatrics, because you expect him not to be white. I think you can easily say that Nolan’s Ra’s is not the immortal from the comics and can infer that the title has been given to plenty of people before Ducard. In the end it makes perfect sense that Neeson is the canonically Middle Eastern Ra’s Al Ghul.
This sort of fiction works by suspending your disbelief that what you see can’t happen. If you really want to cast existing characters in a race neutral way you have to make the audience believe that they are either the ethnicity the character is or the new take on the character makes perfect sense within the confines of the story. That way it’s not jarring and it just is.