After that incident, Ling Zhenfei understood a principle: Spiritual Power wasn't absolute. As long as it was applied properly, even someone of a higher Realm could be killed using ingenious Techniques.
Therefore, from then on, he began searching for powerful Techniques and, very fortunately, Ling Zhenfei timely found the Sky Piercing Finger and Heaven-Splitting Ten Fists, which taught him there were higher levels to strive for.
Both the Heaven-Splitting Ten Fists and Sky Piercing Finger were techniques that compressed one's own Northern Spiritual Energy. After twelve cycles of circulation, the Northern Spiritual Energy would be compressed together and then released through both fists.
When used properly, this Technique could easily kill a cultivator of the same Realm, and even those of a higher Realm could be challenged.