In the realm of magic creation,
a perfect-grade evaluation is the limit ordinary magic can touch.
To achieve a perfect-grade evaluation, merely having an excellent magic circuit design and clear, precise magic structure is not enough. Even if a magician's skill is great, at most he might scrape together a 'fine' rating.
To reach a perfect evaluation, one must innovate.
This is like writing a paper, no matter how many or how superb the cited documents are (references to other magic circuits), or how rigorous and detailed the writing and terminology of the paper is (the composition of the magic structure),
if the plagiarism rate is very low, it can at most be rated as an excellent college paper. To be published in an academic journal, one must achieve certain results in areas rarely explored by others.
An Su's X-ray Illumination Skill was quite novel,
not because its design was intricately crafted, but because it was sufficiently new.