A curse is a form of manifestation of causality.
When an ordinary person casts a curse, they must pay a corresponding price.
For example, Meng Jingzhou's self-taught curse of singularity requires him to preserve his vital energy until he becomes immortal, which is the price he pays.
The Imperial Teacher, who has grasped the nascent form of the Dao Fruit of Causality, doesn't have to pay the price.
All types of trials and tribulations, this is a concept put forward by Buddhism, encapsulating all the worldly sufferings. Trials and tribulations can be regarded as the highest form of curse. Meng Jingzhou's curse of singularity is unworthy to even be compared to them.
After a series of blows, the Imperial Teacher realized that with Fairy Eternity present and Yun Zhi, who could break his desperate moves, present, it was impossible for him to escape.
Since he can't escape, he might as well pull someone down with him!