I recently finished _Blood Meridian_ and then read some analyses of the ending, particularly how the Judge waxes lyrical about "The Dance" of violence as a higher human activity, while the kid dismisses it as base: "even a dumb animal can dance" just as he is sucked back into it.
I do not think that McCarthy intends there to be a single correct reading of what The Judge is; he is inexplicable, uncanny and ambiguous like something from a David Lynch film; however this "manifestation of guilt" reading has to be among the main contenders latent in the book's meanings.
Alternately, the Judge is just a man, the Judge is Satan incarnate, the Judge is chaos and lust for violence, the Judge is a metaphor, the Judge is some other natural force, the Judge is some other supernatural force, the Judge has a deal with Satan, the Judge has tapped into some other supernatural force.
“There he set on a rock in the middle of the greatest desert you’d ever want to see. Just perched on this rock like a man waitin for a coach.”
I’d always gone for a more magical realism approach because of how often his supernatural demeanor is focused on, and because it dovetails neatly with Anton Chigurh being a similar thing in No Country for Old Men.
The author is capable of writing with precise clarity about even the darkest subjects. IMHO, if Mr McCarthy intended there to be an unambiguous meaning, then he would have put it in the novel. he did not, therefor, it is intentionally ambiguous, for us to ponder - above I compared this to David Lynch who is known for avoiding precise explanation his films.
But that is an excellent interpretation.