*You may be interested to know that as a UK-English person, Felix and Mildmay's voices are English in my head, and their dialects work just fine. Felix is RADA-trained RP, and Mildmay is a blend of working-class southern (more earthy and richer than Cockney) with a bit of dour Yorkshire thrown in.*

Me too. I can hear Mildmay's voice just fine in my head but couldn't replicate it out loud, while Felix's accent is exactly like mine when I'm annoyed (it tends to get a bit sharper and more pronounced, which probably says a lot about me using it as a weapon or something equally snippy. *g* )