When you ask me, then Crystal Ball is an extraordinary character. He's looking different from other GI Joe / Cobra figures in his medieval costume. A regular 80s GI Joe action figure had weapons, I mean real weapons like a gun, a rifle, a bazooka, or at least a sword. Crystal Ball came with a multi-colored holo shield instead and (sometimes!) with the ability of mind reading.
To make this guy "A Real American Hero" or at least a member of "Cobra Forces", kids needed some real imagination and creativity. This is one thing why I admire the figure so much. There is something more and mysterious about it. The character has depth.
The other thing is, like I already said once: The biggest rejects are just good enough to get the love of the Toywalker. Crystal Ball is designed as a misfit and he absolutely fullfills his purpose in being a bastard that nobody wants. He's a gypsy, though. "Born of a Romalian father [...] and an American mother [...] Crystal Ball actually was the seventh son of a seventh son... and such men, the gypsies of old believed, were posessed by supernatural powers."
Rumors tell, that the character was developed at the suggestion of Stephen King and his son, Owen, who was a GI Joe fan (http://gijoe.wikia.com/wiki/Crystal_Ball_(RAH)). If the story is true, this would somehow explain Crystal Ball's strange descent, what makes him so special in contrast to regular GI Joe / Cobra team members.