The only angle I can see for it is there was a dungeon where mimics of everyone showed uo, and the final boss was the mimic version of Frieren. In this case Frieren would be the fake claim and Mimic Frieren would be the actual role. Doing something like having Frieren be on an OC story path is something I would probably do as a host, not something I've ever seen Fuji even think of doing.
Aside from that, I'd sooner believe Aura (whose underlings have been Mafia) and Qual (an old demon that used to be really strong but in the present day was job fodder).
@Rej I'm surprised you'd suggest Frieren over those two acrually as both fit pretty well.