undead ninja terrorize Blackmoor seas!

[Havard]

Myself, I'd leave it as Japanese but not give much in the way of clues to players. These guys would be speaking a completely foreign language and not have anything that the characters would recognize or know about.

It depends on the groups tolerance for cheese elements. In my group, once the players started sensing something like this was up, they would stop taking the setting seriously. Which is why I tone down even the sci fi aspects of the setting and leave any R/W connections completely out of it. I remember that we did this kind of stuff in my first gaming group though, with a platoon of Vietnam Veterans, ripped from the movie Platoon, appearing in the Forgotten Realms, after a discussion we had about whether modern firearms would cause 1d20 in damage or something else *lol*.

OTOH my Blackmoor is part of the Mystara continuum which has a parallell world called LaTerre based on Clark Ashton Smith's visions, so not all RW elements need to be tossed out.

-Havard