In his third year after returning to the Academy.
Green, who had been trading potions for all kinds of advanced knowledge, was forced to leave the Library.
His three-year career of collecting advanced knowledge was interrupted by the Academy's summons. The reason was that Green had received repeated reminders from the Academy.
After joining Selestrniel Academy, Green had one obligation left unfulfilled, apart from the duties he had taken on when he first joined.
That was teaching Alchemy. Green himself was a Senior Mentor at the Academy.
Green had been away for the past four hundred years. Now that he had returned, and with only the final hundred years remaining of his five-hundred-year obligation, the Academy naturally insisted that he fulfill his teaching duties.
Most importantly, the Wizarding World was recovering faster and faster. As the concentration of Elemental Particles rose, the number of qualified humans throughout the Wizarding World was rapidly increasing.
The total number of apprentices at Selestrniel Academy had continued to climb over the past few centuries. By now, it had multiplied several times over.
The entire Central Region was flourishing, but beneath this prosperity, a hidden problem had gradually emerged.
The number of apprentices under the Wizards had doubled again and again, until now their teaching staff had become woefully inadequate.
In the past, each Wizard had only five or six apprentices, and some had as few as three or four.
But now, in the Central Region, each Wizard had at least thirty apprentices, and some had as many as forty or fifty.
Since Green had yet to fulfill his responsibilities, the Academy's education department naturally set its sights on him. After one reminder after another, Green finally chose to do his duty.
When it came to the subject he would teach, Green naturally chose Alchemy,