Back at the edge of the mystic realm where Xuan Hao had been looking for the teleportation formation that his disciple should have wandered into during his absence, Xuan Hao finally concluded that the teleportation formation he was looking for had either been destroyed or disappeared along with his disciple. Forcing him to give up on his plan to use the teleportation formation to quickly cross the distance between the outer edge of the mystic realm and where his disciple had ended up.
Because of this, Xuan Hao wasted no time as he rushed in the direction that he could faintly sense the presence of the mark he had left on Mui before having left her to train by herself.
At the very least, because the mark in question was connected directly to his soul, it didn't matter how far away it was or what kind of formation Mui might be trapped inside of, as he would still be able to easily sense her location.