MTL - Space Doctor: The National Hero is a Girl - Chapter 6 let you out

Qin Chen crossed into Taiyi Holy Land as a sweeper, and at the age of sixteen awakened the system. As long as he signed in at different places, he could get different rewards.

Sign in at the Land of Emperor Ruins and get the world’s No. 1 Chaos Holy Body and the Chaos Emperor Sutra!

Sign in to seal the magic land and get the quasi-emperor soldiers!

Sign in at the Refining Hall and get the God-level Refining Technique!

Sign in at the medicine garden and get the medicine of immortality!

Sign in at the Imperial Palace and get the Emperor-level forbidden magical power ‘Resurrection from the Dead’!

…

Qin Chen thought that he would just sign in silently until the world was invincible.

One day, the relics of the Great Emperor will appear in the Holy Land, all the holy places, families, and ancient dynasties have come, and there will be an unparalleled demon king in the relics, killing countless powerhouses, ruling the world, and wanting to destroy the Holy Land.

In desperation, Qin Chen could only walk out, slapped the Demon King to death, and sighed: “I just want to be a sweeper and sign in silently. Why do you force me to take action?”

- Description from novelbuddy

Synopsis below:How did the Avatar universe change when a transmigrant appeared in an unknown village, long before the canonical events? And how are the two islands Kyoshi Island and Uzushiogakure no Sato (A village hidden in the maelstrom)?---Tags: AU, Before-canon, Post-canon, Violence, Death of major characters, Transmigration, Harem, Children, Incest, Romantic. Foul language.

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates

Kieran was just an ordinary part-timer — a high school dropout who had also given up on boxing. With no parents and no real family, he survived by working his ass off every day. He was raised by a man he believed to be his father, but later discovered he wasn't — though the man passed away before the truth could fully sink in. What Kieran didn’t know was that he was actually the sole heir to a powerful business empire, the hidden son of a wealthy tycoon.