Yes! Kougetsu was making it so obvious that she wasn’t Reirin. That being said, body swap magic is forbidden and likely not well known so it’s forgivable that the handmaiden didn’t realize it sooner. Plus Keigetsu told lies to make Reirin more trapped, like how she “stole” the non-existent diary.

And yes, it is funny that all this has taken place over the course of just a week. Those must be some extremely fast growing potatoes. Agriculture aside, the rest of the timeline makes sense, and really sends home Keigetsu’s plight of not even being able to maintain the charade.

As for the mystery, I think it’s clear that Keigetsu knows who the real culprit is. I had a theory from last week that the real titular “Inept Villainess” is Keigetsu because all her schemes so far have only make Reirin happy. But it’s also pretty clear that there’s someone else pulling strings from the shadows, setting Keigetsu up to learn forbidden magic, killing her parents, hiding Reirin’s illness from her, and making her envious of Reirin.

I thought maybe it was someone from the Kou clan, but that seems extremely unlikely after this episode. The Shu Consort seems to be the obvious pick, even moreso after this episode. She “saved” Keigetsu, asked her why she couldn’t be more like Reirin, and now we find out that she was favored to be the Empress until Kou claimed it in the final hour AND the incense she gives the Emperess is cursed too. I mean, the evidence seems overwhelming against her, especially with the last bit. BUT… she seems like the too obvious choice.

Remember, both the Kin AND Shu incense gifts were cursed, but Keigetsu said there’s only one other forbidden magic user. Now there might be a third, extra secret magic user but I doubt it. Moreover, the Empresses’ flashback showed that it wasn’t uncommon for one maiden to give another maiden a gift to give someone on their behalf, as she was given the handkerchief to pass off as her own gift.

So I think someone is giving the consorts these incense jars to use as gifts. I mean, the Kin consort seems to be an idiot, and the Kin maiden seems to be a fair person. But there was that one girl from the Kin clan who gave the hair ornament to Leelee who the Kin maiden said she didn’t recognize as one of the white robes, so that’s suspicious as hell.

Also, I really like where your mind is going with this other dark magic user. Someone who can swap bodies to extend their life or otherwise do mischievous deeds without getting caught. Keigetsu is barely tapping into that power.