Chi Xue could do nothing about Fei Peng's incredible speed. That meant he couldn't prove himself invincible, and there was little point in challenging the experts of the other major factions, so he called it quits.
Although he hadn't defeated Fei Peng, Chi Xue had beaten plenty of others. His undefeated record proved his strength, too. Anyone else who wanted to prove himself the strongest in the You Hun Realm would have to fight him—and defeat him.
There were many experts in the You Hun Realm who wanted to prove themselves invincible and earn the Enlightenment Sacred Tree's allegiance. This was especially true of the Ancient God experts. Though their aptitude might be slightly inferior, they believed that their advantage in cultivation realm gave them a good chance of defeating Fei Peng, Po Tian, and the others.
The core disciples of the major factions thought the same way, so they followed Po Tian's example and began issuing challenges. The first target was naturally Po Tian, who had yet to suffer a defeat, and soon he was receiving countless challenges.
Po Tian couldn't very well refuse people who challenged him openly. Besides, he was a battle maniac, so he accepted every challenger.
Most of those who came to challenge him were Ancient God experts. As core disciples of the major superpowers, they all had excellent aptitude, but none could defeat Po Tian. At best, they fought him to a draw, while nearly half of them were beaten by him.
A gap of one major cultivation realm separated Ancient God experts from experts at the Heaven God Great Perfection level. The difference wasn't quite as vast as heaven and earth, but it came close. Yet Po Tian could draw with Ancient God experts—or even defeat them—while still at Heaven God Great Perfection.