Kyoukai Senjou no Horizon - Volume 8B, Chapter 46: Deciders Near the Flirting

In the year 2220, a radiation source in the Pacific Ocean, tens of thousands of times stronger than a nuclear bomb has begun mutating exposed creatures into horrific monsters thousands of meters long. Mankind’s only hope was nuclear weapons, which only made matters worse. The combination of the natural radiation and nuclear radiation released an incurable and highly infectious virus, turning the 90% of the world’s population into violent zombies in mere weeks.

When Li Xianyu was 20 years old, he received his father’s inheritance, an 18-year-old great-grandmother who was incredibly beautiful.

Li Xianyu: “Great-Grandma, why are you so young?”

Great-Grandma: “That’s because I died when I was 18 years old.”

- Description from Novelupdates

The number one socialite, Song Ci, marries the most handicapped man, Han Zhan!

Arthur got randomly transported to another world. Some people would find that terrifying, but not for him, who was tired of his old life; it was an opportunity.

And, after having bad luck all his life, the tide changed.

It was a world of magic where wizards fought side-by-side with their familiars. Arthur got summoned to be one of these so-called familiars.

He was furious. The thought of becoming a pet was not something he liked. Well, that changed when he saw who his master was.

A hot-woman. And, to make everything better, Arthur was inside the Frostpeak Magic Academy, which only had women students.

“This is heaven. All familiars are beasts, but I'm different. I'm a good-looking man inside a place filled with hot girls.”

When he thought his luck could not get better, he unlocked a system that helped him with everything. Of course, he used the system for a greater good, like getting girls.