Douluo Dalu 2: The True God King - Chapter 8: [DD2]:

Lin Yun, 36 years old, a widower, a mid-level manager in a private enterprise, is a single father, who has recently felt that he is encountering a mid-life crisis. Professionally, he faced adversity; domestically, he was in a cold war with his 14-year-old daughter; physically, he suffered from periarthritis and spoke daily of his agony. In the past few days, he had also uncovered a secret — his daughter was being a “Magic” girl. With the body of a young maiden, she battled extraordinary monsters and protected the city from attacks — this is the common perception of a “Magic” girl. But he was very aware that being a “Magic” girl came with life-threatening dangers. Should he stop her, or respect his daughter’s choice and find other ways to protect her? Gazing at the Heart Flower in his wardrobe, now covered in dust, Lin Yun, the former “Magic” girl who retired 19 years ago, was facing the third major decision of his life.

Kanda Kyoichi transmigrated to Konoha and became a temporary instructor at the Ninja Academy. Fortunately, he awakened the Mentor System.By teaching others, he could earn rewards.Thus began Kyoichi’s career as a “teacher” in the ninja world.Shisui: “Sensei’s unique interpretation of the Will of Fire has given the Uchiha Clan a true sense of direction!”Asuma: “The essence of the jade lies in protecting the people, with the advanced leading the way for the less experienced. Only then can Konoha become stronger!”Kakashi: “He’s my life mentor. He transformed Konoha!”...Years later, in the memoirs of Kyoichi, now the Hokage, he wrote:“I honestly just wanted to be a life mentor!”

Suddenly, the unmarried twenty-year-old Ye Zhizhou had many more relatives, yet it was too late for him to clearly understand the circumstances as he nearly died in a car accident. After that, he somehow managed to survive and was even forcibly bound to a Salvation System.

How is it salvation?

Harems destroy worlds! Preventing a harem will save them!

. . . .

Ok, prevent harems. After seeing the entire system introduction, the corners of Ye Zhizhou’s mouth twitched. In order to return home safely, he decisively began his risky journey—he’d just treat it as if he was playing a large-scale strategy game.

Since then, the people the protagonist would rescue, he rescued first.The businesses the protagonist would make, he made first. The little brother the protagonist would take in, he took in first. The cliff the protagonist would jump off of, he jumped off of first. The gay s*x the protagonist would have, he’d have. . . . Wait wait, can’t do this one, change it, let me change it.

???: No, you can do this one.

Ye Zhizhou (alarmed): Who’s speaking?

???: Your husband.

Ye Zhizhou: . . . .

- Description from novelupdates

Yuki, a high school junior, dies heroically saving a stranger and is reincarnated in a fantasy world, where he discovers an extraordinary and unrivaled power.