The Martial Arts True Skill he envisioned in his mind was theoretically incredibly powerful; it was just too cumbersome.
A Cultivation Technique with a Single Phase Attribute may not necessarily be weaker than one with multiple, but… purity also means a lack of variety, being too natural, making it difficult to generate intricate and exquisite climactic moments.
A piece of iron, in its pure form, can only be crafted into a sharp weapon. Yet, add materials like sinew or bamboo, and you can create an Iron Embryo Bow with immense lethal power, or even a sniper rifle.
This is the difference.
The limit of Martial Arts Killing Skills lay within the human body, so there wasn't much distinction between the multiple and single phases. However, True Skills involve the Divine Soul, and their limits are much higher.
