What Do I Need This Sword For?

The world is chaotic and noisy, with monsters and monsters indistinguishable from humans and ghosts. I am willing to protect the people I care about with the three-foot green blade in my hand. I don't care about the world. I just hope that the people around me can be free and carefree without being affected by the noise of the world. Only use this sword as a guard. There is so much chaos in the world, what does it have to do with me. It's just a big dream. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.