Extended data:
It is recorded in "Eternal Dragon Slayer" that Yu, the sad disciple of Zhang Sanfeng, the ancestor of Wu Tangmen, was dismembered, and the above twenty-four Chinese characters in the empty atrium at night evolved into a set of extremely brilliant martial arts, each of which contained several changes.
Eternal Dragon Slayer: Zhang Sanfeng was accidentally created when he was badly wounded and heartbroken by Tu Longdao.
References:
Baidu Encyclopedia-"Eternal Dragon Slayer"