Klaus would, in fact, consider himself to be a monster. Maybe not as much as he had been in the past - he really was trying to behave himself for Hope's sake - but he was hardly innocent or benevolent. He killed at very little provocation and his kill list could fill encyclopedias.
"So it does. I can't say I'm fond of it. And I would ask that you not spread around the way I acted.
His voice was soft and very English, and did not at first appear to be frightening. A big part of that was because Klaus was only annoyed - not angry - at the moment.