[Her words leave questions for him, ones that leave him curious and knowing enough that having their answers might enable Yuuki to have an even better grip on the situation. To open up avenues of understanding between the two of them that neither even realized about the other.]
How exactly do you mean you were never meant to exist? The very fact that you do is reason enough.
[Honestly, it brings back the painful remnants of Ichiru's life prior to that horrible day that pureblood attacked. Just living had been difficult for his brother, so he understood the mentality but didn't agree with it.
The second question is not so difficult as the first, but designed to draw more attention in a specific direction...]
That book you were given in the beginning. The one that answered many of your questions...
Do you suffer from amnesia every time you awaken from your slumber?