These appear to be special techniques that are fairly simple and only focus on a person's control of strength and soul force. It appears that these are not tied to a particular cultivation and that anyone can use them.

Nie Li uses his control of soul force in order to win against more powerful opponents. He was able to pierce Shen Yue's greater soul force in order to defeat him.[1] He was also able to use his soul force to amplify his voice.[2] Nie Li could even close off his soul realm before he was even bronze rank. This is a necessary technique that is normally learned by silver demon spiritualists and above in order to capture a demon spirit.[3]

Secret soul techniques

Manhua Chapter 22