MTL - Apocalypse Rebirth: Commander, Don’t Move! - Chapter 42 It's the Celestial Sword

Accidentally reborn as the son of the distant cousin of the Squib, the mother of Harry Potter’s friend Ron, and lived in this world as the second generation of Squib for eleven years.

He originally planned to be an accountant like his father in the future, but he didn’t expect fate to play a joke on him, and he didn’t know the slightest bit of magic, but he received the exact same envelope as his sister on his eleventh birthday.

Due to the expectations of his parents, he reluctantly accepted the reality, but inadvertently discovered another secret…

- Description from novelbuddy

"When will people understand.... I'm only half insane?"

This is a world where humans, demons and mysterious beasts coexist.

Humans cultivate mysterious qi. Demons cultivate corporeal bodies. Mysterious beasts cultivate soul perception.

A legend says that in the middle of an endless rainforest, there are extremely powerful existences; they are called demon kings.

Some demon kings have a tyrannical corporeal body, some are experts in illusions.
Some demon kings are proficient in magic, some can even move mountains.
Some demon kings are able to sense things thousands of miles away.

These demon kings rarely appear in the human world. Even if they emerge in the human world, they would reincarnate in human form; assimilating with mankind while seeking to breakthrough realms…

- Description from Novelupdates

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.”