The supporting character's harem is very normal - Chapter 12: Camouflage skill

That day, my head was struck by an unknown object, and after I woke up, I realized that I’m able to, through titles, understand a person’s truest side.

He lived like a king, died like a grandpa... and woke up as a bratty villain inside a fantasy novel.Nice.Born into the mighty Arkanveil family, he’s expected to grow up spoiled, arrogant, and doomed. But sorry, fate — he’s got better plans.Armed with a broken Proficiency Panel, two god-tier Traits, and the mind of a seasoned conqueror, he’s here to rewrite the script.Demigods plotting. Councils scheming. Demon Emperors laughing.They’re all just EXP waiting to happen.Pretending to be a clueless baby genius, he secretly trains, conquers, and stacks power like a final boss.Because this time, the EX-Rank Villain isn’t playing to survive.He’s playing to win.The world’s greatest families have no idea what’s coming. But hey... they’ll find out soon enough.“EX-Rank problems require EX-Rank solutions.”

Liu Duo was a young girl whose grandmother sold her to four brothers with the intent to be a bride. Unwilling, she ran away the following night, only to fall unconscious while trying to get away. Unexpectedly, however, she was reborn with the spirit of a 25 year old woman, also named Liu Duo.

- Description from Novelupdates

Every drop of this family bloodline is stained with sin. They are the embodiment of contradiction; calm yet maniacal, with great memories yet often forgetful. They pledge themselves to their dreams yet often compromise, are angels that are also devils… It’s why I hate them. And also love them.

The only hope of his family, a youth with the blood of elves and devils walks on a battleground of annihilation and rebirth. He wills his way through boiling lava and icy depths, killing on this field of despair to strike down the lofty figure in his sight. One day he’ll grasp his blade tightly and survey his surroundings, only to find no more enemies to kill.