At level 30, pass your class's test and choose your next path.
Reach level 30 in your first job, then talk to the instructor who gave you that job.
Your original instructor gives you the letter to deliver: Dances with Balrog's Letter.
Ask the Job Instructor to begin the qualification test. Defeat monsters in the hidden test map and collect your class's Dark Marbles.
Exchange the marbles for The Proof of a Hero and take it back to Dances with Balrog.
Proof of Qualification