One of the most interesting responses was from a person who thought the mystery figure was the European replacement for Payload. He said the mystery figure was pictured in the promo poster of a store chain that was giving away the Defiant playset as a promotion. That played well with me since it was of a European descent and being a promotional item, that might have explained why I had never seen another one. But as you can see, it is very hard to track down leads when the person swears by their story, and the info seems plausible.