Chongfei Manual - Chapter 170

The world has changed, and so have the people.

Zhang Gong decides to learn light magic, a magic few show interest in and eventually becomes the legendary Grand Magister. While trying to end the continent’s east and west separation in order to unite all of the different races, he becomes every race’s Child of Light.

With the memory of a Level 200, Tier 3 Mage. Lu Yang returned back to his life ten years ago. Destiny made a joke with him. He was betrayed and everything he worked for was taken away. He had to get it back.

The game’s money making methods, dungeon strategy, legendary quest, equipment source, secret blueprints, combat skills. He knows all. See how a reborn player with his brothers swept the country, burned the world and created the legend of The Fire God!

- Description from Novelupdates

The male student, Fukai Nagamasa, ignores his studies for college entrance exams in favor of following the path to chuunibyou. As he fainted during night cramming session before the exams, he realized that he was transported to a parallel world as a feudal lord in the Sengoku Era. Not to mention that suddenly, he was marrying the sixth Demon King, Oda Nobunaga’s little sister, the one who was purported to be an unrivaled beauty?