Sigilus might make a return appearance in Chapter 3. I know everyone is going to say "he drowned!" No, he just drifted away with the current, unconscious. I have plans on how his character is going to change in many ways, and I think he might scrap his alias AND his love for martial arts. I won't tell you anything about what he will do instead, but let's just say that it will be good, and more of his past will be made known, especially to him.
And Shin, well, his loyalty to Gyulim is gone; he has a thing for Nevina now (as I'm sure you guys have noticed).
As for Gyulim...she's pretty shallow, and I have no ideas as to how to carry her throughout chapter three just yet <_<