I wonder what Makima's truth really is. She said she expects Denji to work happily for the agency, and if he doesn't, he will be disposed of, period. On the other hand, if that was all she cared about, it's unlikely she would go out of her way to employ a half-devil and a fiend. While I do feel like she's very good at manipulating simpler people, like Denji, I can't help but feel she does want to blur the simple good-evil distinction most of the world likely subscribes to. Especially in Japan, it seems impossible her own reputation and future career wouldn't be damaged if her experimentations with the more dubious characters as hunters failed. Is she doing that out of pure goodwill or because she herself is already somehow compromised and doesn't have a choice? Her gentle but ruthless behavior could be explained by both alternatives.

Denji really is a simpleton, but his goals are very honest, haha.