Universal Creation: Starting with a God Simulator! - Chapter 44

[An explosive and thrilling story, highly recommended by the Chief Editor himself. A must-read divine book, you’ll regret not reading this.]In the eyes of others, he might have seemed like a worthless fool, but he was revered as the master of appraisal, the miraculous healer, the charming sorcerer, the lord of the Dragon Palace, the invincible war god… With a hand that wielded golden needles against death itself, and another that brandished a longsword, compelling nations to submit, he possessed unparalleled prowess. His divine gaze surveyed the heavens and the earth, while his demonic sight pierced through the veils of yin and yang. He was unmatched in all the world!

Raised to be the perfect soldier for battle, Alexander had risen to be the youngest S rank Merc. After attaining the strength he so desired, his adoptive father had forcefully made him leave the battlefield. Alex unwilling to acknowledge his retirement was given a mission by his adoptive father. "The mission objective is to find a girl in the public High School you'll be attending and protect her."Triggered by the words mission objective, Alexander who had a 100% completion rate, accepted the conditions of the mission. Follow Alexander in his weird, almost comedic high school life.Alex's father: Hey Alex, did you get to school properly?Alex: Affirmative, I reached the designated place on time.Alex's father:So why did you call?Alex: The target I have picked is situated in classroom 1-B, while I'm in classroom 1-A. Asking permission to threaten the Principal into placing me in classroom 1-BAlex's father: DENIED!...

There was once an immortal cultivator fighting for the fate of human beings. Unfortunately, he failed that time; but fortunately got another chance as he was reborn once more as a human, on the earth of 5,000 years ago. With a second chance, he not only would embark on the road of saving all mankind, but also would retrieve his human nature on the new journey that would last for 5,000 years.

- Description from Novelupdates

…but it seems pretty doable.