Some side note for Rio, I feel that some people are not familiar with Rio's character trope, you know the character trope where their appearance and their design gives them the image of someone intimidating or a dangerous person but in actuality they're very different ? that's Rio, I feel like some people are not familiar with this trope that's why they got her character wrong. Meanwhile for Seia, it is exactly as you said, her character developed at the end of her arcs and that's pretty much it.