This looks like fun! I'll link a couple of previous examples of my voice in the notes, but I have a copy of the book - would it be helpful for me to read some dialogue from it? Either way, click the flag to see my form :)
Dramatic, a lot of variation, I think both my accents are in here: https://scratch.mit.edu/projects/829621820/ A fairly neutral character: https://scratch.mit.edu/projects/841558770/
