(Yeah, that really happened.)
The answer is Miia, I guess. She seems a little more developed than the others.
Actually, there's a bit of laziness later on, as characterization and naming becomes even more defaulted.
Like, the Arachne's name is Rachnera. They're not trying.
The mermaid stat block suggests that obsession with _The Little Mermaid_ is a racial trait, not just a personal fixation of Mero's.
Etc.