I found the two pieces of the Masamune sword in the 600 AD era. When I found the second piece, it mentioned someone's name. I assume I have to go to that person to get the sword fixed, but I don't remember what the name was and I'm not really sure what village is where anyway. Who do I have to talk to and how can I find him?
You're looking for Melchior's Hut in 1000 AD.
It can be found near Heckran's Cave on the center island. The same island as Medina Village!