Last night, having nothing better to do, I made up a Basic Annals of the Heavenly King Zhaowu.

The point of divergence is that King Zhaoxiang of Qin, Ying Ji, destroyed Zhou, and Ji Min, a descendant of Ji Wu, raised troops to retake Haojing and declared himself Son of Heaven; this belongs to a branch of real history.
There are a billion details here:
​1. The Zhou dynasty abolished the Shang dynasty's temple-name system, but here Heavenly King Zhaowu restored the temple-name system.
​2. In early times, not every monarch had a temple name; one had to follow the principle that 'zu are for merit and zong are for virtue,' and temple names originally consisted only of 'Tai, Zhong, Gao, Shi'; there was no later practice of using posthumous titles as temple names.
​3. Following the principle stated in point 2, a dynasty in principle can have only one 'zu', unless the dynasty is destroyed and a monarch reestablishes it (with the merit of founding anew), in which case that monarch's temple name can be 'zu'. For example, the founding emperor of the Eastern Han, Emperor Guangwu Liu Xiu, had the temple name 'Shizu'.
​4. The temple name 'Taizu' is generally given to the monarch who first received a fief or first founded a state. According to this rule, Taizu should be King Wu Ji Fa; however, King Wen Ji Chang laid the foundation for Zhou's conquest of Shang, so King Wen was made Taizu, and King Wu was made Taizong.
​5. In the early period, the Zhou Son of Heaven's noble rank was that of king. After King Ping moved east and established the Eastern Zhou, the authority of the Zhou Son of Heaven was no longer what it had been. The feudal lords vied to call themselves kings and recognized one another, such as the famous historical 'Xuzhou Mutual Recognition of Kings' and 'Five States Mutual Recognition of Kings.' Chu, which held only the rank of viscount, even bluntly declared, 'I am a barbarian, and do not use the titles and posthumous names of the Central States,' and usurped the title of king. To distinguish the Zhou king from the feudal lords who usurped the title of king, the Spring and Autumn Annals often refers to the Zhou Son of Heaven as 'Heavenly King' in its text. Therefore the full title of the Zhou king is 'Zhou Heavenly King.'
​6. In the historical background here, Qin is still ruled by King Zhaoxiang, Ying Ji. Ying Ji's mother is the famous Queen Dowager Xuan, Mi Bazi (the prototype of Mi Yue in The Legend of Mi Yue). Qin Shi Huang has not yet been born, and King Zhuangxiang of Qin, Yiren, is still serving as a hostage in Zhao.
​7. Because Qin Shi Huang has not yet been born, and Qin has not unified the realm, there is no title of 'emperor.' When Ji Min raised troops and declared himself, he naturally continued to use the honorific title 'Heavenly King.'
​8. King Zhaoxiang of Qin, Ying Ji, took away the Nine Tripods that symbolized the Nine Provinces, meaning the Zhou royal house formally lost its position as the common sovereign of the realm. But by this time the Zhou dynasty had already enjoyed eight hundred years of dynastic fortune; when Ji Min raised troops and recaptured Haojing, in the eyes of the world it was a sign that the Zhou royal house was meant to rise.
​9. The feudal lords calling themselves kings had already become a fact. To win the help of the feudal lords, Ji Min did them a favor and promoted the ranks of the six states—Yan, Zhao, Han, Wei, Chu, and Qi—to the royal rank. Since the rulers of the six states gained recognition from the Zhou Son of Heaven, they were naturally willing to nominally submit to the Zhou Son of Heaven again, and therefore honored Ji Min as 'Heavenly King' to show the distinction between high and low.
​10. Wangshu Wu was Ji Wu, the youngest son of King Ping of Zhou, Ji Yijiu; hence he was called Wangshu Wu. Ji Min was a descendant of Ji Wu's line, so he called himself 'I am a descendant of Wangshu Wu.'
​11. 'Yu Yiren' (I, the One Man) was the self-designation of the Zhou Son of Heaven. In earlier times, the Zhou Son of Heaven's self-designations included 'Gu' (the Lone One) and 'Guaren' (the Solitary One). After the Eastern Zhou, the Zhou Son of Heaven began to call himself 'Yu Yiren.' Therefore, in the text, the Zhou Son of Heaven's edict (imperial decree) says: 'I, the One Man, am a descendant of Wangshu Wu.'