Toaru Majutsu no Index: New Testament - Volume 14, Chapter 1: Imagine Breaker and World Rejecter — One_Night_Encount.

Allen, an eight-year-old boy from a poor family in the royal capital, is living a poor but happy life together with his mother. One day, however, memories of his previous life suddenly come back to him and he remembers that he is in an dating sim game and that the capital will be destroyed by war if he doesn’t do something about it. If this continues, both he and his mother will be killed! With a sense of urgency, he decides to rise to the occasion in order to save his precious mother’s life and save his favorite character, the villainous young lady Anastasia, the only girl he liked in the game, from her all too tragic and ruinous end. This is the story of a man who isn’t even a character in the game, but who strives with his steely determination and uses all the knowledge he has to turn overcome fate!

Edmund Oakforest is expelled from his family after having a relationship with the king's daughter, who was already engaged to the navy commander. To avoid his execution, he is exiled to the unknown with 10 ships and 100 elite soldiers from the oakforest family, with other workers included. After days of travel, he finds himself in an unknown archipelago. Follow Edmund on his great explorations and the rise of a new empire.

This is a story of an ordinary boy gaining unusual powers from his nightmares… It all started when Lin Sheng experienced something strange on what he thought was just another normal day. He begins to have recurring dreams that lead him on an incredible journey of discovery as he encounters spine-chilling monsters and elusive secrets.

- Description from Novelupdates