Norse Mythology was followed for a long time by the Norse people .Shaake the Norse people were a Germanic group that came to live in Scandinavia and just about anywhere else their ships would take them. The Myth off served to reflect thier lives and vaules and generally entertain them.
Billy gets spirited away to Asgard, where the Vanir of Norse Mythology reside. Although the specific term "einherjar" is not used in the episode, it is implied that Billy was accepted as one of them.
James confronts John Adams about his defending British troops at the Boston Massacre. This illustrates the changing of loyalties that many had during the time of the British Colonies in America.