#unpopularopinion am I the only one who thinks that "Mirror, Mirror" from the original Star Trek was maybe a disastrous mistake? Like, the episode itself is probably one of the better TOS eps; it's not bad. But boy oh boy did it open the door to a thousand unwanted followups and imitators. Mirror universes are up there with time travel among the worst-abused devices for plot generation. It's not the AU itself that's necessarily the problem...ok, sometimes the AU _is_ the problem, and Trek's AU of itself is to Star Trek what Underfell is to Undertale, almost comically grimdark, or wannabe grimdark.