
Yeah you're right but the main reason for him getting angry was coz of Lucaon's safety so just like Kyon was a threat (even though to Ryan he didn't matter much) Christoph was too (while he mattered a lot to Ryan). So we all know Lucaon has been with Ryan for a longer period than Christoph, doesn't this mean that Lucaon would be more important.

This is probably gonna be an unpopular opinion but I just don't think that Ryan's feelings for Lucaon are as strong as his feelings for Christoph just because he's known Lucaon longer. He always seemed more like a cross between a grandfather and a laid-back uncle as far as both Lucaon and Sihan are concerned.

Ah, I get your point now. Well, as paradoxical as it may seem, I think it was due to a mix of both strategy and blindness. There's that stereotype we see in stories all the time that "parents" are blind to the danger that their "children" pose, or know and just don't want to believe it. But at the same time, like Ryan said, Christoph was too close to Cecilia's family; tipping off Christoph in any way could have put Cecilia's entire family in danger, so Ryan had to be very careful of how he approached the situation even after he figured it out/came to terms with it.
If we think about this from a different angle, doesn't it seem like this whole story was about Ryan and Christoph. The way Edwin(The Villain) was after Ryan and for that he used Christoph, but eventually Christoph fell for Ryan. And now if we look at Lucaon's situation, it's like he was there for a sad story while Kyon for healing his wounds so he could love again.
Also I'm lowkey mad at Ryan coz when Lucaon's life was in danger he was ready to kill Kyon(actually not this part got me mad) but when Christoph was involved (this part did) he became soft ¯_ಠ_ಠ_/¯
One more thing the way Ryan died and Christoph's memories were removed kinda gave their story a deeper and sadder end so kinda.. protagonist like(?).
(Please don't hate me for this)