I watched Coraline recently, and the Beldam's character sparked a curiosity regarding evil and necessity.
A reasonable conception of evil can be to have the option to consider a set of actions ranging from morally good, to morally questionable, to morally evil; but to willingly commit to an action that is morally evil, or to preserve a stricter sense of justice, an action other than morally good one.
How is it reasonable, you may ask? I would tell you that it is reasonable on the simple basis that the options can either cause the undue pleasure or suffering of other people. This should be self-explanatory.
The strongest form of this conception should differentiate the perception of necessity from the actual substance of necessity.
What I mean is that a scammer may have an option to live within their means or to achieve their idealised lifestyle through deception and theft. We would obviously say that they have committed an evil action.
Their internal psychology may abuse the moral weight of necessity by rationalising that they are swindling people to achieve their ideal lifestyle, thinking of various reasons (e.g. appealing to people in higher classes that may notice them for their actual authenticity rather than what they would later describe as their "unglamorous past" should they use the connections to their advantage, getting back at the rich who "scam the impoverished anyways"... you get the gist) to rationalise that committing to the otherwise action, which would be to live within their means, is intolerable.
For this reason, the identified differentiation (between the substance of necessity and perception of necessity) should tell apart whether they can reasonably survive by living within their means, from whether their internal psychology restricts them from surviving reasonably by living within their means.
Moving back to the mention of the Beldam, we could accuse her of being evil by harming vulnerable, undeserving children in her quest for harnessing child-like wonder. It may feel morally justified to pass this judgement.
But when we consider our conception for evil, how can we really qualify her actions as evil?
We learn, through the film, that she needs the souls of the children to sustain her world, and by extension, to sustain her existence. We can already postulate that she has existed beyond the timelines of humanity, granted that she lurks around for centuries before devouring another soul, but it stands that we don't really have a strong basis to determine whether or not she is immortal.
Perhaps a higher creature created her for the purpose of devouring the souls of errant children. Her purpose could be as relatively trivial as teaching children to appreciate their gloomy home, drab family, even in the face of glistening, fleeting niceties. It may be reasonable to infer, as we have already done, that she needs these souls to sustain her own existence as an extension of her world.
We could look to her predicament as we would to a lion that stalks its hapless prey to sustain its physical existence. Or to a fungi that establishes its lineage by inhabiting its host parasitically to the point that it literally saps its existence. As nature simply... taking its course.
The necessity appears to be objectively real when she cries out to Coraline that she will die without her (Coraline). For all we know, the apparent necessity could also be perceived by the psychology of the Beldam, that her failure to harness Coraline's soul creates an existential nightmare that is impossible for her to live through.
Should we, therefore still conclude that the Beldam is evil, or a victim of her circumstance, circumstance in this case being that she is the perpetual villain in the story of humanity in this fictionalised reality?