Zhao Ruizhi thought that he had already gotten used to the pain, but he couldn't have known that the pain of labor wasn't a sustained and prolonged one, but one that would ease up, and then hit with another intense burst of pain.
Each time the pain arrived, it would be worse than the last. It made one think that one had already gotten used to it, only to strike with an even worse round of suffering.
Sharky used the opening to try and push the Tai'e Sword forward. Zhao Ruizhi's fingers had loosened up a bit from the intense pain and couldn't hold the sword in place.
But in the end, Zhao Ruizhi was still an emperor who had risen up through a battlefield of blood and flames. Even though he was feeling an unfamiliar intense pain inside, sweat pouring down his forehead in large droplets, he still caught the sword again. The sword's tip was now a hair's distance from his body!