MTL - History’s Strongest Senior Brother - ~ 1803. Only one person

What if an alien baby born in the midst of a major conflict on another planet was sent to Earth to save his life? Born with intelligence and the ability to create technology from any material he touches, he was found by a couple in rural Japan and raised like a normal human.Despite his powers beyond reason, living in a peaceful world forced him to restrain himself. He grew up as a young man who loved high-tech superheroes, but never had the chance to realize his dream of becoming a hero.However, everything changed when he and his classmates were suddenly transported to another world—a world of monsters, war, and chaos. Seeing the helplessness of the humans in that world, he realized that this was the chance he had been waiting for.Not with magic, swords, or ordinary physical strength—he would become a hero with technological sophistication that surpassed any civilization!This will be Ren Takamura's story!

After millions of years spent hunting and battling, the forces of darkness were finally pushed back and eradicated. But as Twilight’s lifespan approached its inevitable end, he made a fateful choice—to reincarnate into the future, where a golden age was prophesied to unfold.Now reborn as Twilight Nightfall, a boy who had lost everything to the world, he remembered nothing of his former life.Stripped of purpose and will, he strayed on the path of despair. Yet, in his darkest moment, a reason to live revealed itself.Chosen as one of the sovereign system holders, Twilight was granted an opportunity to prove himself.With sufficient potential, he could earn the highest privileges, rise to the rank of seeker, and represent humanity in the Astral Realm—a game-like world filled with mythical races, limitless resources, and boundless opportunities.Follow Twilight as he ascends to the apex of the Astral Realm, dominating players and rivals alike while gradually piecing together the shattered fragments of his past life, becoming a legendary figure in all worlds.

The ordinary world is not ordinary, ordinary people are not ordinary, and safe places are not safe.

This is a story of a passer-by male protagonist who is entangled by various girls with strange hobbies or even non-human beings while surviving in the cracks and opening a harem.

- Description from novelbuddy