Lovesick

Mattheo riddle an arrogant cold hearted boy, doesn't have a care in the world and thrives on other's fear, and believes that emotions are weak which he had been taught by Voldemort. Alicia Myers is an intelligent, jovial and gorgeous young girl, quite a stark contrast to Mattheo really.
However, both of them learn things about themselves they never realized alone.
She is the light to his darkness, and he provides her with darkness and danger she never knew she longed.
This is a friends to enemies to lovers trope.