When I Returned Home, My Family Was Ruined

I was born as the oldest of a renowned swordsman family, and became stronger faster than anyone. Yet, I could not stop the dragons, a great disaster that had appeared on the continent. I closed my eyes in my final moments, thinking everything was over. I really thought it was over But when I opened my eyes, I was back in the past. A past that was very different from the world I knew. What? Is this really my body? Why dont I have any mana? Where did the castle go? Whys there only a wooden house left? What? The dragons and humans made a non-aggression pact? A family that had fallen and was on the brink of ruin. A family whose writing of divination had vanished. And a body in which no mana could be found! Ill have to keep myself busy from now on. The great hero of a renowned swordsman family. He is back in the past, in a parallel world.