In the end, the Great Sage broke the rules.

After Chen Yi died, he transmigrated, becoming Tang Xuanzang. Unfortunately, he couldn't disguise himself and was exposed immediately. Sun Wukong: "Where's that bald monk?" Chen Yi: "I...I don't know..." Sun Wukong: "It's good he's dead. You'll be going to fetch the scriptures from now on. You must listen to this Great Sage on the journey." Timid Chen Yi: "Okay, okay, I'll listen to the Great Sage." Sun Wukong: ...This kid is much more pleasing to the eye than that bald monk. (Purely fictional, don't associate it with the original Journey to the West.)