So i rewatched HH recently and decided that it's not as bad as initially thought it was-- there's a lot of effort put into it and the premise of one character trying to redeem the souls of the damned is at least interesting enough to have some potential. But the one thing I couldn't shake was the feeling that it was missing something... until it hit me: there are no sympathetic characters. Not even charlie.
Looking at this from a strictly analytical standpoint, charlie has no reason to exist as a force of good in Hell. There's no explanation beyond the blind expectation that the audience will buy into the fact that the princess of hell wants to redeem sinners just... because she's good, for some reason? The daughter of satan needs a damn good reason to be trying to help people escape damnation or else the suspension of disbelief, based on everything else we've seen in the show, will be completely shattered. It didn't feel genuine when she sang about her desire to help the poor souls in hell, it just felt like a quirky "weird girl" trying to advertise her pointless passion project.
With that said: I propose my solution to almost every plot hole in the show: make Charlie a heavenly messenger sent to hell on a mission trip. I'll elaborate below.