In order to learn the Heaven Crushing Techniques, one's aptitude was extremely important.
The aptitude referred to here was not aptitude in cultivation, but instead, one's aptitude in observing the Heavenly Dao.
Those who had good aptitude would be able to grasp things very easily and progress at a fast rate.
However, those with insufficient aptitude would find it difficult to progress no matter how hard they tried.
Take someone like Xue Zhantian for example. Even though he hadn't joined the Heaven Crushing Sect, the Ancient Dragon Empress saw his potential and agreed to teach him the Heaven Crushing Techniques under strictly confidential circumstances. He was now the most proficient living being at using the Heaven Crushing Techniques below Dao Integration Stage.
This was a show of his aptitude.
Aptitude was far more important than perseverance in this case.
