The people standing around outside were all intimidated by the change happening in the Heavenly Wind Domain. It was hard to imagine what Jiang Chen was going through inside of it. In Jiang Chen's own words, a mountain made of knives and a sea of fire would not be more terrifying than the Heavenly Wind Domain.
The Heavenly Wind Domain was created by the Sacred Spirits. It was used to prevent people from violating the taboos of the borders of the World of Bloody Sea. Therefore, its destructive power was striking. The time limit of 15 minutes was actually the time given to people to consider whether to give up. If they had not left when the time was up, a slaughter would start in the Heavenly Wind Domain.