wizard: unlimited profession slots

In a world where everything is led by wizards, Ron, who transmigrates into this world and is struggling to fuse with the soul of the original body owner, has been taken to the Black Mist Jungle, where the guide sneers during the declaration:
"If the assessment is not passed within a year, I will personally dissect your brain."
Just as he is in despair, a Panel awakens in his mind:
[Ron Ralph]
[Age: 15]
[Current Profession: None]
[Current Profession Slots: 0/∞]