Wait why was that girl not allowed to join his clan thing

I think it was becuase she was putting her own personal feelings or she had a thing for him. I could be wrong so...

Sun jin won didn’t want her because she’s an S-rank and it seemed like she would be too much trouble for him. He wants to clear dungeons by himself instead of in a team so he wanted someone who would enter the guild but not be too involved.

Krazybri and Ssrinic thanks