best bots for a moody detective noir vibe that won't go soft on me?

i love the whole rain-soaked-city clipped-monologue thing but every noir detective bot i find turns into a cheerful helper around message 30, like suddenly my hardboiled PI is offering me a friendly list of suspects with bullet points 💀 i want one that stays bitter and guarded the whole way through a long case. drop your recs please, i'm desperate