To put it bluntly, Sword Intent was the manifestation of Ni Jianshuang's ultimate understanding of the Sword Dao, allowing her to create swords from sheer will to slay her foes. Shen Haoran's Broken Soul was a sonic attack, which specifically targeted Spiritual Thought and will. The furious sound waves instantly severed the connection between Ni Jianshuang and the longswords formed from her Sword Intent. Without her support, those swords were pathetically weak.
BOOM...
A moment later, the ten longswords floating before Shen Haoran could hold on no longer and exploded. The formidable pressure vanished in an instant, and Shen Haoran felt the weight on his body lift. At the same time, the terrifying sound waves slowly faded away.
COUGH COUGH...
