In the mortal world, it is actually very difficult to forge divine powers and secret techniques. After all, any technique worthy of being called a divine power or a secret technique inherently contains its own Great Dao divine intent and arcane mysteries.
You can make something look similar, or even bear a spiritual resemblance, but achieving a complete replication and reproduction is virtually impossible.
Otherwise, all sects, schools, and major holy lands across the realm would be indistinguishable from one another. How could there still be talk of exclusive trump cards or sect-founding divine powers?
Chapter 394