In the excerpt, poole and utterson are comparable characters in that they are both

The answer is brave for anyone who still needs this

is this your complete question

the answer is: round.

in literature, round characters are considerably complex and experience or are subjected to unpleasant situations. as a consequence, they go through crucial sentimental and psychological development, which can cause surprise in the readers. in this case, juan's dramatic transformation is related to the adversities he meets at school.