Li Yunmu attacking Frontline Heaven's Huan Beichen without any provocation wasn't just a reckless action on his part. Since the person was foreordained to be his enemy after they descended to the origin world, why shouldn't Li Yunmu get rid of him here and eliminate one difficult enemy.
At the dragon's tail, Huan Beichen's strength had been suppressed, including his flux energy, dark flux energy, and even the treasures which activated because of flux energy. All of them had been completely useless here.
This was the most fundamental reason behind Li Yunmu's sudden attack.
If he missed this chance, Huan Beichen would have descended to the origin world, and Li Yunmu wasn't absolutely certain of his own victory, given the number of life saving treasures the other would be carrying.
