Rome Must Fall - Chapter 1: Rebirth

A man who was once called the world strongest agent ended up becoming a teacher after his retirement to train the new generation of agents. After many years of training his disciples, he is killed at the age of 60 by the ploy of a secret organization and was reincarnated in another world with all his past memories.Though he was surprised by the magic and the strange species of that world, he adapted very fast to his condition as a newborn and took advantage of it. He acquired special magic and gained a massive amount of strength thanks to his tight discipline in order to reach his goal: resume his career as a teacher which he left halfway through in his previous life.This is the story of a man who based on the memories and the experiences of his previous life, became a teacher who travels through the world with his new students.

Gawain is dead and was transmigrated, but there was a slight problem during the process.
After floating for more than a hundred thousand years on a different continent, he felt that he might need a body to become a complete transmigrator, but he did not expect that…

- Description from Novelupdates

After being summoned in this other dimension world, all of the people that were summoned had their classes awakened. As someone that doesn’t even know English, Kim Sunhyuk had awakened as the lone Dragon Rider. But wait, there are no dragons?!?! They looked down on him, shunned him for being worse than a regular soldier, and called him a dragon-less rider. But little did they know that he would soar the skies on one above them.

A world from another dimension suddenly appeared in the Milky Way galaxy and collided with the earth. A spatial collapse occurred, which allowed the monsters crossing over from the other side to invade various countries, and the earth fell into great calamity.

The military was powerless against the invasion because modern weapons didn't work against monsters from another world. Under the desperate situation, a god-like figure appeared and bestowed blessings upon the humans to awaken their power. From then on, the earth regained its hope, and these extraordinary people were called Realizers.

Tenku Okuihara is a five-year-old boy who dreams of becoming a Realizer to protect the world and his family. But an incident changed his life goal from a hero to a grim reaper.