Rafael Sandoval:
DC's first Latino with his own comic, you'd think that was something, it's not.
Blink for a sec during the history of the DCU and you'll completely miss him. Not a single contemporary writer seems to have ever referenced or homaged him in any way.
Sad.
They dropped the supernatural angle, and made him more street level Texano social justice warrior.
The kind of self-made vigilante who could potentially hang with Green Arrow, Batman types, and what a great way to promote him that would have been. Did it ever happen, no.
That's why most have never heard of him.
He may have at some point been updated to connect him to the supernatural legacy.
To little to late.
There was a four issue Vertigo book by Brian Azzerello called El Diablo, no direct connection (although one could be made)