According to the Tyrant's Record - Acupuncture Chapter, Spiritual Qi and silver needles complement each other. To fully utilize the techniques in the Acupuncture Chapter, one needs not only powerful Spiritual Qi but also compatible silver needles.
Finding such silver needles is not an easy task. The required material is very special; mere silver is not enough. It needs to withstand the pressure of Spiritual Qi.
What happens if the silver needles can't withstand the Spiritual Qi? They become crystal clear and eye-catching, just like now.
People around didn't understand the principle behind it; they only knew that this scene looked like magic, dazzling and cool.
Administering acupuncture also requires a seamless execution.
A steady hand, accurate acupoints, fast speed, and moderate strength are all key to acupuncture.
Lin Tian chose short and thin silver needles because they were to be inserted near the eyes, called 'eye needles.'
