This morning, when I went to see him after his repulse of Van Helsing, his manner was that of a man commanding destiny.

He was, in fact, commanding destiny, subjectively.

He did not really care for any of the things of mere earth, he was in the clouds and looked down on all the weaknesses and wants of us poor mortals.
I thought I would improve the occasion and learn something, so I asked him, "What about the flies these times ?" He smiled on me in quite a superior sort of way, such a smile as would have become the face of Malvolio, as he answered me, "The fly, my dear sir, has one striking feature.

It's wings are typical of the aerial powers of the psychic faculties.

The ancients did well when they typified the soul as a butterfly!" I thought I would push his analogy to its utmost logically, so I said quickly, "Oh, it is a soul you are after now, is it ?" His madness foiled his reason, and a puzzled look spread over his face as, shaking his head with a decision which I had but seldom seen in him.
He said, "Oh, no, oh no! I want no souls.