Top Student: Experience Infinite Occupations - Chapter 313 - One Person One Gun, Like an Elite Force

One day, Luo Jian woke up from his sleep and found himself in a locked chamber where the door and window were all sealed. A note with a few lines written on it was tacked to the wall: “Escape from this room within an hour, otherwise, you will die.”

There is a sequel called Reincarnation Night (轮回之夜) that takes place in the same universe but has different main characters

- Description from Novelupdates

Ethan accidentally rode the wrong train and ended up in Brynhildr Magical Academy where Wizards and Witches are taught on how to use Magic.As someone who didn't have any magic powers, he thought that he would be punished for being in a place where he wasn't supposed to be. Fortunately, due to a stroke of luck, the teenage boy managed to avoid the worst case scenario, and ended up staying in the Magic Academy to learn magic.Ridiculed by many for being magically crippled, Ethan strived to adapt to his new school life with the help of his new friends, who made him realize what True Magic was all about.

In 2120, a massive gateway that connects Earth with the Otherworld replaced the Aels boulder in central Australia. The Earth, representative of science, and the Otherworld, representative of magic, subsequently made contact and two wars broke out. Both wars inflicted enormous damage on both sides, eventually leading them to choose peace negotiations, and thereby marking a thirty-year era of peaceful exchanges between Earth and the Otherworld.Even though both sides chose to coexist peacefully, they each coveted the other's benefits. With the impending arrival of the third inter-world war, Earth's Otherworld combat General Staff Headquarters decided to secretly dispatch an advance team to the Otherworld to conduct pre-war reconnaissance.As a hybrid of Earthlings and Otherworld elves, Luoer, after secretly studying and training for over twenty years in Haiya Academy, which specializes in cultivating hybrids of Earthlings and Otherworld inhabitants, will soon lead his squad into an exciting adventure in the unknown Otherworld.Swords and magic? No, this is a world of guns and magic!

Roy died during a war against the Evil God Cult, but somehow, he returned back in time to 30 years in the past where he was just a boy who awaken his summoning magic.