If I had to guess, I'd say you're right - and the one he's trying to save is Christophe (we received this hint that Christophe's a half, so maybe Ryan chose a pact with Intron so save him), while plotting to get Intron down as soon as he got his hands on something useful...? But my head's spinning, everybody's guess is as good as mine ^^
It's all up for speculation, but I think anyway, that Ryan and Christoph have some sort of bond or obligation to one another. Ryan does seem a very loyal person who does sacrifice his own health for others. To Karis he is essentially a father figure, and he is Lucaon's uncle. Given his close ties to all the main (royal) characters, and the secrecy about his current occupation/retirement such a twist may well be the case.
Yeah we can do nothing but wait and see how things turn out, i highly daubt Ryan batrayed Lucaon that's nonsense, I think he has a plan to take down Intron from inside or whatever, that's why he hid Kyon, to make it easier for him to search for info while Ryan is settling his own part of the plan
I think Ryan has a plan