While Sun Wukong and Zhu Gangxi were sending Jiang Liu'er and Silly Girl to Chang'an, they stayed in an ancient temple and saw a mural of "Havoc in Heaven" painted by someone of unknown date and month on the wall.
This article is written for the fan art of "The Return of the Great Sage" drawn by @Jielin_Huaguoshan's first full-time uncle.
Conception: