"They're chosen by the god Odin. The Valkyries choose some of the slain on the battle field and they go with him to Valhalla, a large hall by the field. By day, all the warriors go into the field and do battle with eachother until they're all killed. Then at night, they raise up again and go back to their halls for drinking, games and telling stories."

Almost like milliways, except without the killing.