Presupposition of the question: the drastic-difference thesis, which is here based on the SEP article on the concept of evil:
Since World War II, moral, political, and legal philosophers have become increasingly interested in the concept of evil. This interest has been partly motivated by ascriptions of ‘evil’ by laymen, social scientists, journalists, and politicians as they try to understand and respond to various atrocities and horrors, such as genocides, terrorist attacks, mass murders, and tortures and killing sprees by psychopathic serial killers. It seems that we cannot capture the moral significance of these actions and their perpetrators by calling them ‘wrong’ or ‘bad’ or even ‘very very wrong’ or ‘very very bad.’ We need the concept of evil.
Now, suppose a category with initial, terminal, and zero objects, a category called Value. Following Kant, if we reverse the appropriate priority of duties/virtues relative to happiness/hypothetical imperatives, we have given ourselves to radical evil. Would this mean that Evil = Valueop, here? Or, to fully capture the essence of the drastic-difference thesis, would we have to go to something more like Metavalue first, with disvalue as an object of some "kind," internally opposite to another object = value, and then take Metavalueop = Evil? Would that be drastic enough, or perhaps too drastic? (As far as interpreting Kant goes, I suppose I should differentiate Diablos Malum from Radix Malum instead of just having generic Malum, here; or then there are diabolical objects and radical objects, as initial, terminal, zero, or otherwise objects, of Evil, but then this makes it seem like Evil is not the opposite of Value or even Metavalue, since reversing the mappings internal to categories of Diablos-objects and Radix-objects together would not give us "good" mappings instead?)
Citation issue: although I have found tantalizing remarks scattered across the Internet about the ethical applicability of category theory, I have yet to find a fuller, broader treatment than this one pertaining to deontic logic in the Canadian legal system. However, as far as I can tell, the word "evil" does not appear anywhere in that article.