Kamonegi-go ga Mahou Ken de Ippai ni Naru

You woke up, in the world of magic swords. You don't know anything about the catastrophe five years ago in This world. You'll be working as a radio operator, and you'll be attacked by a black magic sword. Who is the "Messenger", who knows the terrible power of a black magic sword, the identity of a magic sword, and everything? Your choices determine the fate of this world.