When Roger Sweet originally pitched He-Man to Mattel, the idea was that "He-Man" wasn't exactly a character: he was a toy system. He-Man, like Ideal's Captain Action, would have been a single doll body that could become anything by buying different accessory packs. To demonstrate the idea, Roger Sweet and Mark Taylor took some "Big Jim" toys and customized them into a military man, a spaceman and a barbarian. Vykron and his three outfits represent those three original prototypes.
When sold at SDCC, Vykron was dressed in his barbarian gear - if you bought him from Mattel's website after the show, you got him dressed in one of the other two outfits. They all come with all the gear, though, so it really doesn't amount to much at the end of the day.
At SDCC, the set also included a copy of DC Comics' new
He-Man and the Masters of the Universe comic featuring an exclusive variant cover. Well, it's the same cover as the regular edition of #1, just presented in the original black and white line art rather than being colored. It's a cool choice, I just wish I'd known it was coming before I bought the issue at my local store.
Vykron is an interesting figure - not "great," by any means, but interesting. And even then, mainly interesting to huge nerds who know way too much about the history of MOTU as a property. So, in short, us. The barbarian outfit is really the only one that feels like it belongs in Eternia - yes, technology has its place in the story, but that technology has a specific look, and neither Tank Top nor Space Ace quite blend to the right extent. But if you find space in your MOTU collection for this weirdo, you can dress him however you want.