I had a theory that Ryan shared his energy with Christoph as well, because he is actually weaker than he looks and gets ill all the time. Christoph that is .. maybe Christoph is just jelous then :D
I also thought that, maybe Christoph is the son of Edwin but since he was so weak when he was younger, he was not worthy of his name and Ryan actually rescued him from Edwin... ? I'm pretty sure, Ryan knows who Edwin is but not who he actually is... like he might know him from a party but doesn't know that he is the Intron guy and also the father of Christoph or smth... I'm pretty sure the answer is right under their noses... and Christoph was also brainwashed like Kyon and it was all planned out by Edwin so Kyon and Christoph give him information unknowingly.. Edwin might have loads of servants like that.... so he knows exactly where, when and how people move around and knows how to time all the attacks.
Ok this is my theory but I think Christoph is trying to kill Lucaon because Ryan is getting weaker because Lucaon..there was this incident where karis tried to wake up ryan but ryan is not waking up..this is maybe because he shared his power with lucaon..maybe christoph loves ryan so much that he rather die than seeing ryan die..hence he put the vs solution into the tea and is prepared to face the consequences.