Actually, there is a reason why people on the Douluo Continent are not enthusiastic about researching and developing Self-Created Soul Skills.
Take the Xuan Tian Bao Lu, for instance—a cheat code handed directly to the protagonist by the original author, perfectly seamless to use.
Take Ghost Shadow Perplexing, for example. Even when cultivated to the realm of complete mastery, it is at most equivalent to a ten-thousand-year soul skill.
Chapter 28