This was because the metal used to forge the two pipes was extremely special. It was immune to soul and mental power.
Therefore, one could only destroy the two pipes physically.
However, the cylindrical structure above could not be damaged.
Once this thing shattered, it would release a terrifying destructive force that even a fifth-realm Demon King would not be able to withstand.
The range was very wide, and even hiding in the nearby void would be useless.
The exact reason was unknown to the third-realm Demon General. It only knew that the cylindrical structure could not be broken. Su Jingxing's Primordial Spirit was too far away and could not guarantee that it could accurately destroy the pipes. For this reason, it could only be done close up.
The cylindrical structure could not be broken, which also proved that the information Su Jingxing's Primordial Spirit had obtained from the soul of the second-realm Demon General was true.