A cultivator's greatest fear was the heart demon oath. The heart demon was the greatest enemy of a cultivator in the process of cultivation. Once invaded by the heart demon, even if you didn't die, you would still end up suffering from Qi deviation. Therefore, in the cultivation world, no one would easily make an oath, let alone make a great oath on the heart demon.
Li Lin had taken the great vow of the heart's devil to become Zhao Hai's servant. This was something that no one had expected. No one would have thought that a nascent soul expert would be willing to become someone else's servant. It would be difficult for him to make any further progress in his cultivation in the future.
