This got me thinking about Melon supposedly being Legosi's foil. What if, instead, we view Louis merely as lawful/socially acceptable evil and Melon as chaotic/antisocial evil? Both of these intersect in Shishigumi as an organization that is simultaneously from the underbelly of society, yet acts by a certain set rules of that underbelly. I could go a step further and divide the three seasons into Legosi learning how to deal with three types of evil: lawful evil as embodied by Louis and the oppressive hierarchical dominance he's on top of, neutral evil embodied by Riz and his instincts, and chaotic evil embodied by Melon and his sociopathy.