“ - The self-proclaimed first ruler of the Kappa kingdom and a mysterious kappa-like life form. Turns people into kappa by pulling out their shirikodama.”
there’s no concrete evidence for this, but i think Reo and Mabu were originally part of the kappa kingdom! (or at least, anti-otter.) ep 6 and novel spoilers mentioned under the cut
there are specific tweets [X, X] showing Mabu being Highly Concerned by the otter marks appearing around town, suggesting that at least Mabu (and his superior) are alarmed by the otters. (Reo, on the other hand, gives no real indication of noticing the otter signs.)
as mentioned in my other post, this prince figure’s snout/chin looks suspiciously otter-like...
the anime also never actually said this was Keppei—the implications were clear, based on the princely attire and color pallet, but is this actually the Keppei we know? i have my doubts, especially considering we see the “kuro keppei system” in action at the otter HQ when Haruka’s box is returned.
there’s also the fact that the dark energy coming out of keppei looks sort of like a not-yet-formed zombie underling, and its eyes are the same as the eyes in the kawausoiya dance as stated in cocolocochanpo1′s tweet. this is probably the “kuro keppei” mentioned in the previous instance?
however, Mabu and Reo were hostile to this princely figure in the flashback even before the dark energy appeared, which suggests (at least) two possibilities:
possibility 1): this really is Keppei, and Mabu+Reo are otters apprehending their enemy at long last, or
possibility 2): this ‘Keppei’ is an otter impostor, and Reo+Mabu are kappas who had cornered the fake Keppei, only for Mabu to be taken down by the “shattered desire”. I’m guessing this pushes Reo to make a deal with the otters, who had taken over the kappa kingdom at this point.
judging from the unseen otter superior Reo+Mabu talks in ep 3, it seems as though the only thing keeping them in service is the death threat, and the empire lowkey suspects them of treason—not to mention Reo’s insincere platitudes at the end of that scene. this makes me think that the two were originally from the kappa kingdom but they switched sides when Mabu was incapacitated (the otter empire offered a deal to prolong Mabu’s life and Reo took it out of desperation?)
there’s also a novel spoiler [X, read at own risk] i think of regarding Reo and Mabu’s origins (which may be part of ep7? who knows). the emphasis of “rain is a blessing in this country/in this land” which is Very Generic, but also strangely insistent that “this land” has a special fondness for the rain? it’s anecdotal evidence at best, but i do find the emphasis of the importance of rain to “this land” and its inhabitants a bit unusual... in mythology a kappa dies if its dish is empty/dried up, so the importance of rain in the passage could point towards Reo and Mabu being in the kappa kingdom when they met?
(i also suspect Reo was originally part of the otter empire, sent either as an infiltrator or abandoned in kappa territory, but has no loyalty towards the otter kingdom due to how he was treated by the empire, especially after he found a home in Mabu)