Remember Acrata? She was featured on Smallville back in Season 5 in the episode “Vengeance” and got her own web spin-off series The Vengeance Chronicles.
Acrata, a.k.a. Andrea Rojas, is a crime fighter who strikes against organized crime in her home country of Mexico. Acrata could either be passing through the United States or later seasons could find Black Lightning traveling the world to assemble a team of superheroes, the Outsiders.
The character’s powers include shadow teleportation and martial arts skills. Someone who works in the shadows is a nice contrast to a hero whose powers illuminate the darkness. Combine that with the chance for even greater diversity by getting a Mexican superhero joining the series and you can’t go wrong.