Quote Originally Posted by Skyblade
Delita was manipulating her. She was the means to his ascension to power. He cared nothing for her personally. As soon as she outlives her usefullness and becomes a possible threat to him, he kills her with no remorse.
Except for Delita manipulating her, I disagree with you completely. The means to his ascension was his own doing, not hers. I think the fact that she wasn't a real princess furthers the idea that he gains feelings for her. She becomes royalty from common birth just as Delita does. He makes the mistake of letting her live and not telling her the truth which ends with her killing him.