Overlooked

Vale heard her speak but had to ignore her since he was afraid that something had gone wrong in his Spell Light.

Master Heinz had repeatedly reminded him that he was the first Practitioner of the Malefic Branch. He is the first recorder of the Spell Dispersion and Incorruptible Body. In short, the negative effects of these spells would be first known and experienced by him.

Heinz could only theorize what kind of side effects he'll obtain, and that is obviously not a hundred percent accurate either.

According to what he learned over the past year, these adverse effects could result in mental illness, blood thirst, spirit possession, spell model corruption, or even their life.

Vale also had to ensure that his Spell Model was firm and wouldn't just collapse and result in some internal injuries. That is the common problem among original spells after all.