I am waiting for My Rio Blast to arrive, so let's talk some Rio.
So, Rio Blast, not to be confused with Rio Pacheco, is MOTU's resident Cowboy. According to Vintage Lore, RIO IS NOT FROM ETERNIA... I REPEAT: RIO IS NOT FROM ETERNIA. That fits with the whole "Cowboys don't fit in MOTU because Eternia is a more barbaric society,"
Rio being an alien, helps give the character some, well character, aside being "The Cowboy". Like the Cowboy cliché, he may be at home on the range, but at the same time Eternia is NOT home. That is a great angle to explore for him (and the fact that He-Man is such a huge jerk that goes to fight in other planets instead of helping Rio return home). the UK Comics (I think) had Rio partner up with Snout Spout and something about him being afraid of snakes.
His being a Cowboy can make him a bit of an odd fit to MOTU, but at the same time, he is SO MOTU... He's got guns EVERYWHERE... He walks through life as if he was playing Contra with the Spread Shot at all times.
We have guys defined by their action features (Mekaneck, Extendar) so, a walking Arsenal makes sense in MOTU. I understand he is not for everyone, especially when MOTU itself is very rooted on Sword and Sorcery. The thing is Why people accept Trap Jaw, Man-e-Faces or Roboto, when they have problems accepting Rio Blast?
It has to do with Rio Blast being "the American Cowboy" I'll not go into the whole Cowboy ripping off the "Latin American Vaquero" (Guess where the Term Buckaroo comes from). Like I said, MOTU is well rooted in Sword and Sorcery... Like Dungeons and Dragons, to name a popular Fantasy game. Ninjor, barely gets a pass since the Ninja is the ancient Oriental Assassin. The Cowboy is a more Recent thing, so it is very removed from the sword and sorcery theme. This is another reason why the Disqualified Create a Character entry: Gangstor doesn't fit MOTU... but I digress. When we have KNIGHTS, Barbarians, Ninja, Samurai, a Cowboy does look a bit out of place... Luckily we have Elephant headed Firefighters. A Frogman, a Furry Potato Bear-like creature, a Skunk man and a Witch Doctor Mask/Vampire thing... Classics makes it easier with a Blue Roid Rage Stan Lee, a Purple Chrono gimp, and Cobra Commander cosplaying as a knight.
Rio's main issue is that he is a later wave figure. Those were either cheaply made figures (Black guy with Fisto Armor and a new Weapon as gimmick) or defined by his gimmick (Drag Racing thanks to wheel on stomach.) He also lacked Filmation support. (While a character with the same gimmick appeared on SHE-RA, that guy was a Hordesman, not a hero.) As of the writing of this article, he is still available on Mattycollector. He seems like a cool addition, BECAUSE of how Odd he is. He seems to stand out compared to say, Extendar. His MOTUC version also looks like Sam Elliot... Kinda wished he looked like the spawn of Charles Bronson and Chuck Norris (like the 80s toy)
Long Story short, if Rio had gotten some televised media appearances or had been among the earlier waves, perhaps he would have gotten a bit more love.