Newcomers testing the waters.
Originally, it was just a little transparency for diving, but because there was no one in the whole page of the directory, Ye Xiu was reborn after his death and set up ABO, with memory and system.
Alliance, also known as the Omega Alliance, AO is better in technology and physical fitness (finger flexibility). And because, in the world, A has high hopes and is not accepted by people.
Ye Xiu, alpha. The rest are omega.