Here’s a thought experiment:
Any writer knows the crux of any plot demands conflict. And conflict usually means one or more of the characters are going to suffer on some level. If characters undergo emotional and/or physical turmoil that could potentially leave them blubbering in the corner on the bathroom floor (assuming they survive), it is one aspect of how they might reach the level known as the Christ Figure.
Okay, so using Darth Vader as an example is a bit of a stretch. Those who have been around long enough first came to know him as the ultimate bad guy, and the Christ Figure is usually associated with the likes of Frodo or Harry Potter. But authors like to experiment with archetypes, and the best antagonists also have depth. Tennessee Williams and Flannery O’Conner were writers with a knack for giving that element to detestable characters.
It’s easy to see why protagonists do get most of the limelight. After all, there is usually the element of sacrificing oneself for the good of others, and people who are wicked aren’t inclined to that sort of thing. If, however, the villain is more misguided rather than evil, the Christ Figure could possibly apply.
Even an egotistical motive could come into play. In one of my books, Wail of the Tempest, a malicious character winds up dying in the course of an unexpectedly noble act. There was no revelation or change of heart involved, but the heroine of the story nonetheless recognizes – and appreciates – the unintended sacrifice.
So the Christ Figure can have a myriad of uses, even on characters that are not so Christ-like. It doesn’t even have to be limited to the main actors of the tale, but can also be scattered around in various doses on the supporting cast. The corner of the bathroom has looked (or will look) appealing to most of us at one time or another, so we can identify with those characters.
Regardless of one’s religious predilection, this is a pretty powerful component in story telling that will be around as long as there are stories to tell.