What effect is most clearly created by the structure of the following sentence?

Question

 Quentin, the timid one, the one who was described as afraid of his own shadow, stood up to defend his younger brother when he was threatened by a bully.

Answer 1

This sentence sets up a contrast between the descriptions about Quentin and his behavior. The descriptions at the beginning tell us that Quentin is afraid. We would not expect him to stand up to a bully. The possible reason is in the second half of the sentence. Maybe Quentin cares so much for his younger brother that he overcomes his fears.