It turned out to be so simple. All he needed to do was kill a demon of the same level.
He couldn't be too strong, nor too weak. If he was too weak, he wouldn't be able to conceal the aura of a human cultivator. If they were too strong, the evil spirit's aura would completely cover the cultivator's aura, and they would be stopped by Mother Earth's power attribute.
Of course, this requirement would not be too precise. It would be enough as long as they were at the same level.
The clue itself was still very important. Otherwise, even if Lu Qing had encountered a powerful demon at the divine sea level and killed it, he would not have had the time to think about fusing with the other party's aura. He might have missed this opportunity.
If what li Daoxian said was true, then Lu Qing's next goal would be very simple: Find a demon at the divine sea level and kill him.
As for whether the other party was lying or trying to incite Lu Qing, he felt that it was unlikely.