MTL - Two-dimensional Yellow Hair System - v15 Chapter 31 Dean of Education Brainiac

The unparalleled Demon King Ye Xuan, who was able to heal the death or the living alike and holder of the medicine Holy Scripture, was betrayed and killed by his fellow Demon Kings. But he reincarnated into the body of Ye Xuan, the prodigal son of the Ye family and vowed to himself that he would return to his peak and take back everything that belonged to him!

- Description from Novelupdates

As a lawyer back on earth, Lin Yun had never lost a case. He owed his success to three things: two blessings he received at birth (a photographic memory and the ability to comprehend anything he studies) and an indomitable will he forged himself.

Six months ago, tens of thousands of black phantom towers appeared all over the world, floating above the cities. Chemists, physicists, religious people… all of them could do nothing.

The world was once at war with 10 alternate worlds. This was known as the Concept War and our world won 60 years ago. All of this was concealed so no normal people are aware of this fact in the current time.

After the death of his grandfather, the high-school student Sayama Mikoto is suddenly summoned by the giant corporation IAI. He learns this world is headed for destruction due to the acceleration of the Minus Concepts. To prevent this, negotiations must be undertaken with the survivors of the other parallel worlds so their 10 concepts can be released.

And so Sayama is caught up in the final battle to clean up after the Concept War which left behind so much enmity.