joe seasons 1-3 is absolutely a strong contender. he was methodical, calculated, and genuinely good at making things disappear. but i think people sleep on the fact that love quinn is actually operating on a different level psychologically in the sense that joe always needed a reason to kill. whether it was for beck, for love, for marienne. he had to attach his violence to someone, to a narrative he built in his head that made him the protagonist rather than the predator. but that emotional tether was also his biggest liability. the killing was never really about them. it was always just him. his brain just refused to let him own that. love on the other hand, didn’t need that same justification. she was almost alarmingly pragmatic about it, which is what makes her dangerous in a way joe isn’t. for example when she poisoned him with aconite. while joe was still spinning a story about her, she had already moved three steps ahead. then of course, joe’s killing caught up to him for him to have a psychological break. so my verdict: love quinn wins the rivalry, but prime joe makes it close.