I just saw that Nasu is on the same sprite sheet as some of the other FC World Characters. I don't know if it's true but it may be that Nasu was intended to be part of the FC World. Nasu wasn't part of the game in Madotsukis room till version 0.05 (source: Kikiyamas changelog).
Fulminis-ictus (talk) 14:21, January 3, 2014 (UTC)