You can select from three characters in the demo: Monkey, Bing, and Ding.

Monkey

If you are familiar with Chinese legend, you’ll notice that Monkey’s outfit and skills are a metaphor for Sun Wukong - also known as the Monkey King - a figure who features in a series of legends that can be traced back to the Song dynasty.

https://en.wikipedia.org/wiki/Sun_Wukong

Bing and Ding

Their appearance and outfits are inherited from Zhao Yun and Huang Zhong,

two military generals from the Three Kingdoms period, famous for their triumphs and military skill.

https://en.wikipedia.org/wiki/Zhao_Yun

https://en.wikipedia.org/wiki/Huang_Zhong

Also, Their name is a reference to the “Hundred Family Surnames”, a book that introduces 504 Family surnames in china which was composed in the early Song Dynasty,

https://en.wikipedia.org/wiki/Hundred_Family_Surnames