Demon was not as angry as Renaud or even Leila and Xavier.
Rather, he felt a little guilty for stepping away from Sister Purple. It was obvious Sister Purple was acting on goodwill when she tried to greet and touch him. Unfortunately, he could not bring himself to do it.
To him, it was more difficult to face Sister Purple than the others.
He had never been close to her because he was isolated to prevent the development of too many human feelings. The few times they met when they were children, she would try to hug him, and it made him uncomfortable.
After all, one of the first lessons he learnt was that contact was the quickest way to get killed. He had used those techniques himself on numerous occasions. He only needed to brush past a target, and they would be gone in a few minutes.
However, these were not the real reasons that he was not close to Sister Purple. Over the years, he had begun joining the group, even though he remained isolated due to his role as an assassin.