Ryan cannot read memories. That's why he asked for Cecilia's help to read Kyon before this. Because he can't do it himself.
Lucaon also asked Cecilia to help heal Kyon. This means that Lucaon does not have the power to do it himself.
royal's powers are all different, from how I see it.
I think Christoph is making Ryan sick so how??? we see, I do also believe that he will die in order to safe Lucaon. The intruder was there to kill Christoph in order to success poison Lucaon without any hope to reverse the solution. Well maybe I'm over thinking all possibilities.
U r not over thinking,, I agree with u 100%
http://www.mangago.zone/read-manga/royal_servant/uu/royal_servant-chapter-51/12/
Did Ryan by any chance go through Christoph’s memories? It seems that after putting his hand on Chrsitoph’s head, he seemed like he “knew” something. Or maybe I’m just seeing things lol, but I do suspect Christoph of being the one who poisoned Lucaon.