In which country is there such a law ? And there is parody and parody, a lot of different parody situations, so i do not believe that they could win in court, since Duke A.Blizzardo is just a name that might have or not have anything slight in common with Blizzard.
As Blizzard added so many Easter eggs related to PNJ names (Harrison Jones, Haris Pilton, ...) in their games, it would be absurd that they sue Bossland for Blizzardo.