Medieval Fight

Brian, a college student lose consciousness after an earthquake. He wakes up in a sewer completely confused. Follow him on his journey through a medieval world where he will have to fight to survive. My first language isn't the english, so don't expect a good grammar. I'm using google translate and my little knowledge of english to create this story. I'm relatively a newbie in the creation of stories. Tags: Overpowered, No-Harem, System, Medieval, wars, Kingdoms, Aventurers, Guilds, Fantasy races, no magic, tragedy, Cunning Mc, Cruel Mc. The cover picture isn't mine. If the author have a problem with this, please, tell me and I change it quickly.