In theory, Xu Yuan, who only has Integration Body cultivation, should not be able to penetrate Mu Nuo's defenses.
No matter how weakened Mu Nuo may be, he is still a Saint. It's like trying to compare a burly man over two meters tall who's turned into a thin bamboo stick with a child trying to take advantage of him; the child still wouldn't be able to.
But there are always exceptions.
If that child is encased in an exoskeleton, the situation changes entirely.
Perhaps it was his innate talent at work, but after the initial anxiety, Xu Yuan quickly adapted to the markings on the back of his hand without any difficulties.
Although this thing was sealed on him by Tian Ye using Dao Charm, it felt as though it were a natural organ of his body. Moreover, unlike involuntary organs like the heart or lungs, he could fully control it at will.
