It was almost laughable for him to say that to her when he knew he didn't change much, even claiming many lives, for he had always been that way, unfeeling.
He felt nothing even when he claimed the life of his first victim — his father. Taking many more lives to exert his dominance and make certain his way to the throne did not phase him at all. He felt the same way as always.
Maybe his father was right to call him a devil. A monster born amongst humans. His abilities were also another reason why he was labeled that way and probably why he was so nonchalantly. But he never cared.
Evans was the only one he had some kind of emotions towards. When they first crossed paths, he felt pity for the young elf, and that was when he realized he wasn't as emotionless as everyone, including himself, had thought.