Shin High School DxD - Volume 1 Chapter 3

After transcending to a new world, Ye Xuan miraculously obtained the Swallowing System.

As the last abyssal demon in the world, Wen Long was pulled into various worlds to do tasks by a guy who claimed to be a system. The goal of her mission was to save those villains who had been blackened for various reasons…

- Description from Novelupdates

A major event happened recently to the demonic sect – their powerful sect master suddenly went missing.

Everyone comforted each other: “Don’t worry, the sect master must be out pursuing fun, and so on.”

“Well, that makes sense.”

They waited.

Waited and waited.

Waited and waited.

Waited and… Everyone slammed the table: “We’ve waited so long! The sect master must have met with a mishap! Look for him!!” Numerous disciples therefore ran rumbling down the mountain.

On a certain day of the month, a certain sect master opened his eyes and thought in confusion: Hey, who am I?

- Description from Novelupdates

This story is set during the end of the Sui Dynasty, a time where multiple powers struggled for supremacy and power.