I think that as well, i have been saying that since a long time ago. Sure it may be slightly influenced by yuuki but i think what they give as a reward, as well as how they give it, is influenced by their subconcious. For the Absolute Existence that is the chief i think she subconciously wants someone she can be weak and submissive to instead of being "on" all the time.I still think the rewards are in actuality just the deep seated desires of the girls being brought out by the lending process and not entirely Yuuki's own wishes. Can't wait for Ren's second reward session.