These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: High Plains Drifter
Alternative Character Interpretation: Originally, the stranger was the marshal's brother and may still be, the script was changed to leave it up to the viewers. The most common are the ghost of the Marshal, Death or even Satan himself.
Acceptable Targets: The cowardly of course. The townsfolk are repeatedly shown to be either unwillingly to confront or even care about the evils within their own town.
Dead All Along: The Stranger. it's implied he's the spirit of the dead marshal returned to take revenge on both the men who killed him and the townspeople, some of whom were responsible for the plot to kill the marshal and the rest too cowardly and greedy to do anything about the murder.
Eastwood makes it ambiguous. He COULD be the spirit of the dead Marshall, but on the other hand the original script claimed he was the dead marshall's brother and the film does nothing to refute this. If he were the marshall's brother, he'd still have the same name i.e. the same last name, as the marshall. Plus The Stranger seems to do a lot of the things that 'out and out ghost' The Preacher couldn't i.e. have sex
What an Idiot: The townspeople have their ambush set up and ready, the gunmen ride into town, and what do they do? Cower down and refuse to shoot.