Because he had never studied magic before, Sui Xiong spent almost a day's time to sort out the common spells with the use of a Directional Spell. Thereafter, he successfully converted himself into a Master of Spells.
That was when he realized that magic was indeed, very useful.
For example, take the day before at that little conflict at the tavern; he could, in fact, use a Mass Illusion Spell to settle the problem. After all, it was just to let everyone witness a scene of "two burly men beating up a black-haired traveler." It was not the least bit important whether that scene happened or not.