A mythical question
by Peter Hill
Question: I'm writing a novel based on mythology, the main antagonist is from mythology but I am aware that other franchises have used Nergal in their comics/video games.
Should I proceed with using him as my antagonist if others have used him?Answer:
Mythology is in public domain. It was created long before the concept of copyright, and its authors are long dead.
Therefore, anyone is free to incorporate characters from mythology in their fiction, and do whatever they want with the characters.
Sure, you won't be the first person to use Nergal in a story, nor will you be the last. Similarly, there are hundreds of stories about Thor, Isis, Robin Hood, King Arthur, Paul Bunyon, etc. written by many different writers.
Some very popular characters get films made about them every 5-10 years, so they can be discovered by a new generation. Nergal is less well known, but as you say crops up in the works of various authors.
Where you could get in trouble is if you are using characteristics of Nergal that are drawn not from mythology but from a more recent author's interpretation of the character. For instance, let's say someone wrote a story about a version of Nergal had a lot of characteristics, habits, or props that were entirely that author's creation and do not appear in the mythology. Perhaps a film is made with this new version in which the character is given a distinctive costume or look. In that case, that version of Nergal would be copyrighted and the image might be trademarked. You could still write a story about Nergal, but you would need to be careful to only borrow traits from the mythology, not the recent book or film version. The same is true with comic book or video game versions.
Of course, you are also free to create your own updated version of the character, for which you would then own the copyright.
As always, I should point out that I am not a lawyer and this is just my understanding of how copyright works based on my reading.