El Diablo, like almost everything about Suicide Squad, sucked.
There are latin superheroes in the Marvel comics, but comics in general has the issue that all of the biggest heroes are white men. The lone exception being Wonder Woman who is part of DC's holy trinity...though recall that for a long time, she was in stores about bondage and her first job with the Justice League...was answering the phones while the boys saved the planet. So....not exactly the feminist icon she's portrayed as today.
Black superheroes are doing a bit better than other minorities in comics, but let's be honest, Black Panther is a weak character and that was a weak movie. I know, we HAVE to love it because underrepresentation and all, but if we're really being honest, we all know it was "meh", right?
The best black superhero character in comics, I would argue is Storm of the X-Men, but she's unfortunately trapped in Fox's X-movies which have STUNK...and consequently her movie treatment has STUNK. Storm is complex and a great character, and hopefully now that Marvel Studios owns the X-Men again, maybe we'll see a good representation of her on the big screen.
I would argue the best latino superhero was actually Zorro. Now, it is something of a debate as to whether Zorro counts as a superhero, but if powers aren't a requirement (and Batman says they aren't), Zorro was arguably the FIRST superhero. He had a secret identity and all of the trappings of a superhero story, and predates Superman.
The latino superhero character owned by the big two comics companies are...kind of terrible actually. I don't think that's intentional. They've tried making LOTS of them....they just haven't worked out or caught on at all.
It's hard making breakout characters. Most of the best known superheroes were made in the 1960s or earlier. Even white male characters after that period have a low 'hit rate'.