Actually, Tie Dan just acted on a whim, seeing that guy's Nascent Soul was so burly, he casually stabbed with his sword.
Experimenting leads to true knowledge, after all, it was a self-created sword move, used to test by killing, relying on Wind Escape to break through and stab straight, until the Lightning Sword hit the opponent's face as expected, everything went as Tie Dan anticipated.
Yet, it's unclear if it was the Primordial Spirit Technique of Luofu Mountain, which indeed had some intricacies, different from the mixed cultivators, or if it was a lack of sword power, causing the damage from the Thunder Qilin Pill's Primordial Spirit to not materialize.
Tie Dan didn't expect that even after stabbing the person to death, the Nascent Soul remained so spirited, lively, capable of transmitting sound through Divine Sense, speaking human words, with clear thoughts and vivid memory, causing him some bewilderment.
