Shin High School DxD - Volume 1 Chapter 4.1

Scream out.Awake and pour out the grudge left in you onto me.Then, I shall save you.

Zhao Chuchu was reborn in a time before the apocalypse. As soon as the space was filled with supplies, something fell from a high altitude and killed her. Then, she transmigrated, becoming a small villager in an unknown dynasty. She started this new life by taking out the natives, dealing with the plague, and becoming a divine doctor in one fell swoop. Using her fists, she gained high status. She bullied those scums until they cried for their mommy and begged for mercy. She produced large quantities of rice, beans, and sweet potatoes… She could do everything, and she earned a lot of money with that. Everyone watched as she reconciled with Xiao Xiucai. They watched until a baby was born, as well as until Xiao Xiucai became the top scholar and smoothly became the Chief Minister. Then, everyone waited for the day the Chief Minister would divorce his wife, who went through hardships in life with him. They waited and waited until the couple had grown old, the two living together for the rest of their lives.

The dawn era after the end of the half century has gradually rebuilt the order, abandoned civilization, and is full of undivided violence and desire.
The noble and powerful pioneers are in charge of the city, and the evil and mad plagues are in the wilderness.
Pure human beings who cannot mutate are the weakest, dominated by the rulers of the pioneers, and are not as good as animals in the wilderness.
A purely humanized young man with a worldly experience has quietly entered the WTO, holding a three-foot long knife and a long-distance desire to boil in the world of purgatory. From the nameless name to the sorrow of the Supreme Court, the name of the black ride is resounding!

- Description from Uukanshu (translated)

Every human on Earth was transformed into a summoned monster and was summoned to another world.