HxH: Apex Predator - Chapter 13: Crimson Claw X Fierce Battle

The apocalypse descends, zombies and monsters appear, followed by System Leveling, which grants skills to all survivors.With the collapse of law and order, some become powerful while others remain weak, and so the dark ages begin.

Gu Mingxi and Pang Qian were next-door neighbors, classmates, and deskmates. From year-to-year, even when the class seating was rearranged, they would still be deskmates. They grew up together like a pair of brother and sisters despite having different parents; if it was someone else, then their parents would probably have already arranged their wedding. However, Gu Mingxi was different.

[You have entered the dungeon at Gwachun Station’s 1st Exit.] When former high school student Kang Woojin finds himself returned back to Earth after being forcibly summoned to a foreign planet for 20 years, he soon finds that Earth is not the same, normal place as he once remembered it to be.

Lin Tianlong, 19 years old, a polytechnic school graduate. With mastery and control over electrical energy, he displays his unparalleled sagely medical skills, accepting the hearts of beauties on the side. Starting by helping his sister-in-law’s small clinic which was on the brink of closing down rise from the dead, he then proceeds to bring prosperity to a private hospital previously in a business slump. Socializing among the officials from the sectors of politics, commerce, law, literature, education, and health in Flame City, he’s drawn into the power struggle between the officials. Businesswomen, doctors, and nurses, attractive policewomen, teachers, pretty loli girls, charming married women, mature beauties – all of them fall to his clutches as he establishes his business empire and a harem of beautiful women.

- Description from Novelupdates