Whatever blood relation Ciel and Eugene have has been dilluted by time, but Ciel just seems so immature compared to Eugene, like while they were flying on Wywy, it kinda felt like Eugene was so much older compared to her while they were talking, which he mentally is. I wish Ciel's feelings for him will remain as some sort of subtle crush, none of the whole clingy and possessive crap most females around male mcs in manwhas do.