Porthos is absolutely wonderful and I love all of his threads with everyone. I really admire how you can bring out all aspects of his personality. I am fascinated by all the headcanon you have for him and how you incorporate little details in his every interaction.
I think this is particularly important for a character who is so defined by his role as a soldier but who is taken into a completely different context when trapped in Kiseki. This applies to Arthur, as well, whose core character also revolves around his role as a king. It'd be so easy to handwave or dismiss these aspects of their personalities most of the time, excusing it with the game's setting, but it never feels that way.