Yeah, it doesn't work as "Here's the problem-free happily-ever after!" He used her as an accessory to murder, and she became the kind of person who would voluntarily cooperate with psychologically torturing people, and you could have interesting relationship dynamics there, but not a sweet little happy ending. (Also, I wasn't against them, but also wasn't actively shipping them? Like basically the idea of them being together was just..."Okay, but what else is also happening?" for me.)

It sounds like it might not go well, but it would go really interestingly!