Inside one of the books Angus borrowed, he found a copy of a detailed method to do the transmutation technique spell that is written by Archmage Bern himself.
He chose to practice this technique inside his manual battle system. After using it over the years, he could select an animal or other easy opponent for practice.
By using this method, he could practice or learn new spells to his heart's content. The only downside is he doesn't have any control of his real body when he is training inside the manual battle system.
This makes his real body in a vulnerable state. However, with the tight security inside the academy, he doubts there will be any intruder for the time being.
He also found that everything he did inside the manual battle system is reflected on his body be it wound or his body development. He could also take out any weapon or things from his wristwatch storage device inside the manual battle system.