You posted this thread in the correct section. By the way, I also like the artwork on Vintage MOTU card backs.
I really admire the Buzz-saw Hordak card back artwork as well as Prince Adam's.
The only mistake on Prince Adam's card back artwork is that He-Man's sword is purple instead of grey. The instructions artwork, however, shows Adam's sword also in purple instead of pink so that it would not blend with the background.