Doesn’t that sunglasses girl have the same power as that Hiruko in the underground lot that gave Kiruko extreme life-threatening hallucinations, where Kiruko’s limbs were chomped and then Maru’s kiss snapped Kiruko out of it (ch 19)? So I think that girl becomes that Hiruko.
That expression made it seem like it was no longer Robin, but agh, we have to wait to find out.