by James Eatock: http://bustatoons.blogspot.com/2006/11/scared-of-invisible-warriors.html
From issue thirteen of the UK Masters of the Universe Adventure magazine here is an interesting couple of panels from a story titled "Inside Castle Grayskull". In these panels we see the Ninjor, Blade and Saurod flee when confronted by the magic of Castle Grayskull. Reminds me somewhat of "The Secret of Grayskull" from He-Man's season two...