I will make a controversial claim here, that Wimmer is actually drawing upon the female version of the Monomyth in a manner of speaking, or rather an alternate interpretation by Valerie Estelle Frankel.
Specifically, the first variation is Confronting The Powerless Father. Earlier in the film, we learned that Dupont was the creator of the Gun Kata, a martial arts extension to firearms that is a basis of Cleric training.
He does not seem to be powerless at first; after all, he seems to know about Preston’s actions all along (see Not Without Incident: Master of Two Worlds), and his challenge to a Gun Kata duel suggests he knows all about Partridge as well: “Be careful, Preston, you’re treading on my dreams” (the reference to Yeats). But despite creating the Gun Kata, Dupont is disarmed by Preston, and so he tries to appeal to Preston’s newfound sense of emotion, to avoid the killing bullet. How can he kill someone who is living and feeling?
But Preston sees O’Brien’s face in his mind, before her death. This would suggest Atonement with The Mother, or rather, The Goddess. Yet there is an atonement to a Father– just not Libria‘s Father, or Dupont. Preston’s response of “I pay it gladly” is an echo of Partridge’s earlier line: “A heavy cost. I pay it gladly” when Preston asked him why he forsook the idealism of Libria. Partridge is sort of a Father in this sense, especially considering Preston echoed other words and actions of his earlier in the story as well.
Killing Dupont, who is the false Father, leads Preston towards obtaining the Ultimate Boon, which will be the next part of this series, leading towards the end.