When the Five Divine Elements were exposed, Duan Ling Tian only had to deal with the threat from Wu Hong Qing, the Temple Master of the Title Temple, and Mi Xuan. However, he would have to deal with almost everyone from the various Devata Realms because of the exposure of his prominent divine artifact with an artifact soul.
Perhaps, he could hide in one of the mundane realms. However, it would be detrimental to his cultivation since he might be lulled into a sense of complacency in the mundane realms. Apart from obtaining the Divine Elements from the top five Nine Stars Gods of War in the Nine Serenities Battlefield, this was also one of the reasons he decided to come to the Nine Serenities Battlefield.