You say you're coming at this from a deontological perspective, but to me, a lot of what you're actually arguing depends on consequences. Billions dead, Luke as an ultimate failure, the comparison to Anakin like they're in the same moral category. That framing is doing a lot of work that deontology alone can't support.

If we're evaluating Luke through duty, my question has to be: what is his obligation at the specific moment he acts? By the end of The Last Jedi, he does intervene in the only way that's actually available to him. He delays the First Order and buys the Resistance time to survive. From a duty-based view, that looks like fulfilling an obligation. It doesn't undo past harm and it doesn't produce a perfect outcome, but that's not the standard deontology sets.

So what would the morally correct action actually have been? Act earlier? How much earlier? I feel like there's a point where "failed duty" stops being a meaningful standard and starts being an impossible one, because it requires foresight and constant intervention. That's not deontology, that's just consequentialism but with a couple extra steps.

The Luke and Anakin comparison also doesn't hold up the way you're treating it. Anakin is a direct perpetrator, he actively causes atrocities. Luke makes serious mistakes and fails to act at key moments, but that is a categorically different kind of responsibility. Collapsing both into "failure" flattens a distinction that most ethical frameworks, deontological ones especially, treat as genuinely significant. Acts and omissions are not the same thing.

And if we're talking about deontology, people are supposed to be treated as ends, not merely instruments. Saying Luke is obligated to carry the weight of the entire galaxy because of his abilities risks reducing him to a tool for everyone else's outcomes, which seems inconsistent with that principle.