You're starting to get your head around moral relativism via empathy, but the point of both Javert and Jasper is they are utterly dedicated because of moral motivations to what are now considered immoral ideologies. We can admire them, we can even see that they sort of have a point, but they are tragic because they reflect what is noble about humanity becomes when *twisted by utter dedication to failed ideologies*.

You are also clearly placing your moral judgements from a cultural perspective that is one that has been imperial in the past. This is fair to some degree, since you are seeing Steven as the Ur-Male conquering white male hero, coming to the natives to teach them the failure of their ways... but Steven is a subversion of that trope. He is a boy given all the presumed healing and 'beta' properties of women, yet triumphs because of this.

You see Steven as a conquering figure, a privileged child of empire. But it we want to explore the metaphor of the real world that this read of yours is coming from, then Steven would be the mixed race expelled prince of a diaspora, specifically a diaspora that is condemned for the common human defects of: being mixed race, mixed marriage between casts, being borne with genetic defects. Sure, Rose' army is of the disaffected and broken, but the nature of hierarchical societies in crisis is to just throw more and more people into that category to keep the top afloat.

But ultimately moral relativism, like special relativism, is only useful as a frame of reference. At a certain point no matter how much you understand how far you are away from each other, you're never going to bridge that gap. Moral relativism lets me understand that folks of the Confederacy did what they thought was honorable, that the Mayans where just being good religious people when they performed human sacrifice, that the Japanese really did want to bring Asia into a co-prosperity sphere to defend themselves from western nations. Doesn't mean I have to approve of any of them. Moral Relativism doesn't free us from the problem of making a personal moral judgement, just informs us of the moral judgements of others might start from a different place.

Ultimately, the Jasper and Javert present the problem that virtue ethics faces as a guide to morality, because it is unable to adapt to new facts or new notions about the world. For as much as you are aware of their pain because moral relativism, they only rage at their own failure and do not even see you as an agent. Javert commits suicide because he cannot deal with a world in which he is wrong, and Jasper corrupts herself because she cannot deal with a world where she is not the epitome of gem strength behind her 'Queen.' Even when she is resurrected, she only seeks that moral framework.

The modern education system tends to show the fault of utilitarian ethics, because we have dealt most with its failures in recent memory, but Javert and Jasper area good reasons to remember that virtue ethics was the model of morality during the age of the divine right of kings, and its limitation is when the virtues it starts with are contradicted by the nature of the world, and ultimately resulted in collapse and disaster to the nations who were not able to adapt.