Funnily enough, in Limbus, Envy tends to be really common with IDs that have the Sinners fully embrace an ideology or community, so they actually have a surprising overlap with IDs that have strong themes of camaraderie.
Well you do bring a good point about that fact/quirk about Limbus Identities and their sin affinities for different skills. Though I could point out even in identities that fully embrace ideologies/communities like the Middle IDs for Meursault or Don Quixote whose central theme is 'family'/'family bonds'. And we're acknowleding the most prominent sins within an identity could either show their view as a character in that mirror world and how it changes their personality, that with Envy there is a motivating discontent, either simmering underneath the surface while still believing in the best of a movement. Like with the Pequod Trio basically all sharing similar sin affinities with Pride and Envy - it could espouse that they would share an envy towards other people, regular people because their current fate in the mirror worlds is way worse and could be improved. Ig as a form of escapism. Though I'm probably big rambling and looking too deep into this tbh
In that sense, I feel like Envy is moreso the other side of the coin from Kindness/Empathy rather than just it's direct opposite. You can't truly envy someone unless you understand just how good they are/how good they have it. Someone who has the Sin of Envy, by their very nature, cannot be someone apathetic towards others.
Not gonna lie, when I was doing some shallow research on the 7 deadly sins and contrasting with the 7 heavenly/capital virtues; I was using the table from Wikipedia and hardcore jumped at that information in making the assumption that they're two complete opposites, that I acknowledge because your reasoning does make fair sense that they complement each other. Though I do want explain my reasoning in why I jumped on the bangwagon hardcore about the two being opposities, is that I was thinking about intent.
To explain this further using an example: In a situation where you are interacting with someone who is definitely in a better situation than you (Wealth, Healthy and loving relationship with a significant other, well-adjusted mental health, etc) and is talking about said situation that has started to go downhill, and you can't help make comparisons between yourself and them.
I think with Envy and Kindness - it's all based on what you do/want to do with that person: In either you want to ruin that person's current situation and drag them down to a lower level and you can reap from the rewards. Or you can either sympathsize with that person and attempt to make that situation better for them. Delivering good vs delivering evil, kinda thing if that makes sense?
Since what makes things sinful is despite thinking about wanting to do evil towards a person, committing said evil towards them is the sin/ The action instead of the thought.
That's how I view that they're both opposites, like as reactions? Than thinking towards Empathy vs Apathy relationship though I do see where you're coming from.
Not gonna lie, it did take me a while to respond to this and I wanted to do some research before replying to this because it was the type of response for me to sit down, do some research, reread and ruminate on it for a while before actually replying kinda thing. Oof.
Also voting period is gonna end in less than two hours!
The votes look pretty close between 'Original Sin' and 'A Soul Lost in Wonderland' (Alice!!!) though I haven't sat down and completely tallied them down so im making the assumption.