Lin Yun came to issue a challenge just because he was idle.
Watching the Snow Maiden fight every day, starting every battle with a 1v3, which eventually turned into 1v5 as the fight progressed.
Lin Yun was afraid that, one day, as the Snow Maiden's battle experience improved and her control of the Fulong Circle became more skillful—oops, not hula hoop—she might even conquer the Mountain and Sea Pass single-handedly if she continued to fight, possibly taking on ten enemies herself.
The Xuanwu Godly Soldier was indeed terrifying.
Previously, the Book Immortal explained that The Emperor and the four kings altogether possessed ten Divine Artifacts, but in Lin Yun's opinion, the Fulong was the most powerful.
Other divine weapons were either strong in offense or functional items, and by their names you could guess their uses, but the Fulong alone was adaptable for both offense and defense, securing an invincible position.