I gotta say…if you were going to make a western about young Bill Munny, Scott Eastwood would be the guy you would hire to play him.
Jackson is a veteran of the Civil War whose young wife is kidnapped by Mexicans (the film is intentionally vague on this…other than they are Mexican). He sets out to find her. Along the journey he crosses paths with the cruel Ezra. Ezra keeps showing up at the worst times, leaving a path of bodies.
Diablo takes what could be an impediment, Scott Eastwood looks remarkably like his father Clint, and uses it to it’s advantage. The audience fills in the rather loose sketch of a character with what we expect from his father’s westerns. Jackson is a loose sketch of a character until about the last half hour of the film.
Eastwood does not quite have his father’s charisma (at least not yet), and so it benefits him that the film allows the viewer to fill in the blanks. Walton Goggins plays the mysterious Ezra with a real undercurrent of menace. Why is he following Jackson? Why is he so quick to kill with no remorse?
There is a moment late in the film that saves it from being a generic imitation of old Clint Eastwood films. Diablo is not perfect, but it is a decent western that seeks to subvert the expectations they audience brings with them.