Just for reference, if you put "Spoilers, Including Ending Spoilers" in the title of a thread, people will expect spoilers - there is no need to put a whole bunch of spoiler tags throughout your posts.

- He almost always talks about Caius with a negative attitude, scowl on face, etc.
- He refers to Yeul as 'my Yeul'. He does not refer to Caius as 'his Caius' at any point, even when there is supposedly a 'clone' or something around - he just calls him 'the real Caius'.
- He most likely will not kill Caius because he does not like to kill in general - this is stated by Caius at some point near the end, I think? The other reason would be that, since Yeul always comes back to life to be with Caius, Noel would not want to kill something which he feels makes Yeul happy.
- He's clearly into 'his Yeul'. The thought of their reunion drives him to keep going on numerous occasions. And in his 'dream world' where he is supposedly in his happy place, it's smiling with Yeul, not with Caius.