I think Black Manta is actually an interesting villain, and probably the only logical choice for an Aquaman film. I’m thankful they didn’t set Aquaman up on a mission against some evil oil drilling subsidiary of Lexcorp or something like that.
There are a lot of interesting tidbits they can pull from the various origins DC has plotted for the character over the years. In one, he starts off as an autistic child that is being housed in Arkham Asylum, while another story has him being kidnapped at an early age into sexual slavery on a ship. As a black man, one iteration of the character even had him trying to figure out how to get black people to dominate the ocean. If I had to place my bets, I’d go closer to the Arkham version of the story. Currently, there are some rumors that tie Karl Urban to the role, but fans would most likely revolt at the whitewashing of such a famous black character.
Confirmed for the film alongside Jason Mamoa are Amber Heard as Mera and Willem Dafoe as Nuidis Vulko. Aquaman opens July 27, 2018.