MTL - Law of the Devil - Chapter 517 [Brothers reunion]

Shu finished the final chapter of a hated apocalypse novel, only to wake up inside it hours later. In Zoxhia, dungeons open without warning, monsters flood the streets, and even the strongest heroes die miserable deaths.The only reason Shu has not joined them yet is a cheat no one else has ever seen: a Domain that can grow into an absolute safe zone. Armed with incomplete knowledge of the story, a dangerous system, and a world already heading for ruin, Shu has to survive, grow stronger, and change an ending where the demons win and everyone dies.discord: https://discord.gg/WkyX6NuZZA

Haruto Hayase was a normal high school boy in his third year, living a quiet life until his younger sister, Haruka Hayase, joined the same school. Haruka’s beauty and charm made her the center of attention, quickly becoming the school’s prima donna. But when a notorious gang leader set his sights on her, he did everything in his power to protect her—only to fail tragically. Haruka was brutally assaulted and tortured, and Haruto himself suffered an agonizing death. However, in a twist of fate, Haruto is given a second chance, waking up a year before the events that shattered his life. Armed with the mysterious ‘Debauchery System Slave’, he vows to exact revenge on those responsible. This time, he will use his newfound powers of the system and charm to seduce the loved ones of his enemies. From their mothers, sisters, and lovers to their closest friends, Haruto will make them his. His enemies will suffer as he steals what they hold dearest, ensuring their downfall in the most devastating way possible.

After accidentally falling, she actually finds herself bound to a Second Female Lead Counter Attacking System!

A world where God will grant abilities called Skills to those who come of age. The protagonist, bestowed with two skills, uses them and rises to an existence called a hero.