Kyoukai Senjou no Horizon - Volume 3B, Chapter 54: Inexperienced Meeting Participant

When a boy in a medieval fantasy world wakes up with the memories of his past life, he discovers a secret buried deep within his mind—a highly advanced AI companion. This AI, a relic of his previous existence, holds the knowledge of a futuristic world filled with technology, science, and innovation.Armed with this unprecedented advantage, the boy embarks on an extraordinary journey to transform his medieval surroundings into a thriving futuristic utopia. From reinventing agriculture to creating advanced cities, he introduces ideas far beyond the comprehension of his peers. But his vision isn't without challenges—power-hungry nobles, skeptical commoners, and ancient magical forces stand in his way.

After dying in a tragic accident, Oscar was reborn into a lowly tribe in an ancient world of great magic where only the strongest survives. Following the decimation of his family, his only solace comes in the form of a remnant which resides in his body.Live the tale of powerful warriors and deadly monsters, and tell the story.

This story is centered around the man named Yi Ji-Hyuk, who has spent 1000 years in a Medieval Western fantasy-like world before returning back to the modern-day Earth. When he returns, he finds that his home is facing monster threats, and that humans with superpowers have appeared to protect the innocent people of Earth.