One Sword to Find the Way Home

The modern soul falls into the ancient world. I wanted to survive peacefully, but I was pushed to the forefront by fate. With modern knowledge, he can work step by step, from being an ant to holding a sword in the world. He single-handedly changed the fate of troubled times. When the world returns to peace, Only then did he realize that the real problem had just begun - how to return to the original world? The road ahead is unknown and friendship is hard to let go. He will make the most difficult choice between the world and the way home.