Dark was quiet for a moment, allowing Loki to speak and either confirm or deny what he already expected. Ah! There it was, indeed. He quirked a brow and canted his head to the side, "Truly?" then smiled. It wasn't the smile of a good man, but rather the smile of the darkest of villains whose had his very goal reached without flaw.
"Wonderful!" he clapped his hands together, brought the tips of his fingers to his lips and chuckled, the sound a dry grating noise that spoke nothing of mirth. "Then you are mine, completely. Entirely." His boyish jubilation was a mockery, a perverted twist on the happiness of youth. It was wrong. Utterly, inherently wrong.
And of course Mr. Dark's insistence that Loki was his completely wasn't entirely true. More that it was.. merely what Dark wanted him to believe. Because, yes, he did have power over him.. as expressed in the fact Loki was unable to speak of things Dark did not wish him to. But that power was never guaranteed. Loki could fight back, though Dark wished the man would remain ignorant of that fact. He'd love to have to hurt him, but fighting down his circus acts was never a business he wanted to be doing when he could be luring in the souls of other people.
"You can feel me. Likewise I know you, your strength. I know your innermost self, the parts of you that you deny. I can smell it, and how delicious it is! It tastes like heaven fallen into hell. You will join me when I leave this place."