Old ninjas don't die they just disappear...
Actually it's an illustration for Ninja Poetry at tastes like chicken http://tlchicken.com/view_story.php?ARTid=2367
I haven't read any of those Lustbader novels since I was a kid.
From your idea and description I guess it isn't related, but is this inspired by the Eric Van Lustbader novel of the same name?
Get art in your inbox! Stay up-to-date on the latest happenings.