well, let's focus on the main male character's personality. Maybe he throughout the series he starts to realize what it means to carry a mark. And fears that he will become one of the city people, who are taught to think that the townspeople are tainted or need to be taught a lesson. Fearing that he will become of the those 'monsters'.
His playful and childish love during his childhood, develops into a romantic and mature kind of love for Amelia. He is can get a little too overprotective and can act a little iffy around a different kind of person. To new people that he and Amelia encounter, he will be a little hesitant and reserved, but once he is warms up to them, he is can show his true personality.
To basically sum it up, he is like a cat around new people and a dog when it comes to Amelia or good people like the townspeople.