After Scar saved Dian from Edmund Huang's assault, he found himself constantly drawn to her. Also, Dian's treatment toward him seemed to have changed and because the two sisters-Dian and Dannah almost looked the same aside from the difference in their hair and eyes, it became easy for him to be comfortable with her. Besides, these days he felt that Dian needed him in a way and such need got him attached to her.
He could see through Dian's eyes that she was not happy with how things turned out, especially with the decision of her father to get her married to Edmund Huang and yet she could dare not defy him. Scar could see her hidden suffering and he knew somehow, like Dannah, she needed someone to understand her.
After the incident, his relationship with Dian deepened and because Dannah was out in the South to attend to her first mission, he spent more time with the second miss. Thrilled with this new blooming friendship, Scar always took time to check on her.