He never had a little sister, so he had also subconsciously thought of her as a little sister. Furthermore, in the orphanage, even though there were many kids younger than him, he couldn't play with them because they were afraid of him due to his unusual appearance.
However, Cyril didn't get such aversive response from the siblings. He could assume that it was because half of his face was now similar to a regular person, which was why they didn't find him scary to associate with.
Regardless, the feeling brought forth from playing with Calissa unexpectedly brought joy to his heart, which had turn cold when Silvia passed away. Even if the joy he was feeling was only slight in comparison to his vengeful and cold heart, Cyril still appreciate it in the moment.
…
