Breaking through point by point.
The sword skill created by Xialing Saint during the World General period encompasses all the emotions, including the subtle grievances and affections of a maiden. Its execution is ghostly and ever-changing, achieving the intent of Great Perfection.
Lin Mo's 'Melancholy Mist Rain Sword' is filled mostly with sadness and longing. This arose when the old Demon Clan witch attacked him, preventing Xia Mengdie from recognizing him and watching coldly from the side. This gave rise to great sorrow in his heart, allowing him to comprehend the 'Melancholy Mist Rain Sword.'
The Melancholy Mist Rain Sword is about great sadness and suffering. Lin Mo broke through Xialing Saint's sword skill by using immense sorrow and suffering to overcome joy, anger, sorrow, and happiness.
If the Xialing Saint herself were to execute this sword skill, she could reach its peak state of perfection, and Lin Mo's method of breaking through it would not work at all.
