User blog comment:SpookyBoogie27/Light Novel Spoilers/@comment-82.178.42.183-20140208042505/@comment-1359322-20140208043938

Ajuka isn't cold blooded you know, just because he doesn't care about Diodora doesn't mean he doesn't care about his clan. Also Ajuka and Diodora are brothers, Ajuka would've known about Diodora's hobby and to what extend Diodora goes just to for his hobby  and is disgusted by his brother, that's why he doesn't care about Diodora.