I Made Up Forbidden Spells, and They Actually Worked?

After crossing over into a world of magic, Dean Bruce was mistaken for a powerful sorcerer. Though he initially intended to sternly refuse the beautiful woman’s request to become her mentor, she offered him far too much to say no!
Completely clueless about magic, Dean Bruce had no choice but to make up spells on the spot. However, when he saw the astonishing power unleashed by the beautiful woman after chanting his random incantations, he was stunned.
The spells he had carelessly invented… could they really comprehend magic and even forbidden spells?
As Dean Bruce ascended to the pinnacle of magical prowess and became the Archmage, he candidly answered a reporter's question during an interview with the Alliance: "I never understood magic. I just made up a few incantations, that's all."
People were in awe of him—this, they believed, was the true humility of a Grand Archmage!