Indeed, Long Yi had nearly figured out the composition characteristics of the sword's radiance in an instant. However, as a wielder of the Four Dragon Marks, he naturally couldn't perform the true sword's radiance. Nevertheless, he could opt for the next best thing. He performed an incomplete version of the sword's radiance, which wasn't as sharp as the complete version, but was more than enough to envelop the entire Crystal Greatsword. With this, he was able to face off against Cain!
After landing one hit, Long Yi did not give his opponent room to breathe, and a series of attacks followed. Even a fight has its rhythm, with emphasis on the continuance of techniques. Once one person falls into the rhythm of the other, it's hard for them to break free.
To Cain's surprise, he was gradually becoming the one who found it difficult to break free!
The reason was simple – Long Yi had an inexhaustible burst of brute force!