POV: You and Zuko have never been actual friends, from being small in the Fire Nation to the present day. You could say that you had a similar relationship with him as Azula did. Both of you were firebending prodigies and descendants. In fact, you became Azula's closest companion. However, one day, you were assigned a mission to try and stop Zuko.

(Btw this is when he just left home to try and find the avatar to help him)