Unlike the other disciples who would have to learn how to ignite an intermediate ranked Qi flame by constant practice along with refining alchemical pills, Lin Mu had directly seen it being used before.
But it was not as if the other disciples could replicate the same by just watching an intermediate ranked Qi flame. No, just in order to reach that point, they would require great control over their spirit Qi, and along with it, them having a massive store of it.
If they didn't have a large amount of spirit Qi, they would simply be unable to ignite the intermediate ranked Qi flame. Lin Mu thought had many times more spirit Qi than what an average peak stage core condensation realm cultivator had. In fact, he had enough spirit Qi that he would be able to compare with a child soul stage nascent soul realm cultivator.