For those of us geeks who grew up with heroic fantasy and Dungeons and Dragons, magic swords have intelligence an ego, and/or a mission are nothing new. Thinking about it, I wonder where those ideas came from?
Words like Geas, Weird, and Fate do come to mind as rough translations for Wahyu.
I'd also point out a rather odd book
The Sword of Heaven (Amazon Link), which is the reportedly true story of a shinto priest's (successful?) attempt to save the world using a magic sword. Interesting story, whether you're a true believer or not. If this did happen, I hope that collectors leave the sword where it is!
Best,
F