The reason Lu Tianxing did this was actually quite simple; he knew that many people were aware he possessed the Creation Source Technique, but they were skeptical. This time, by injuring the Black Shadow, a veteran late-stage Mythical expert, he clearly informed everyone that the rumors circulating were true. The cultivation technique he practiced indeed allowed him to strengthen through battle, break through realms in life-and-death situations, and challenge opponents at higher levels without worrying about unstable foundations.
Lu Tianxing believed that once this news spread, the Yang Family and Tang Family would choose to use their full force against him, sparing no effort. That's because they feared his breakthrough; with peak mid-stage Mythical power already capable of injuring late-stage Mythical veterans, if he were to advance to late-stage Mythical, wouldn't those experts be utterly powerless against him, at his mercy? No one wants to see that happen.
