Ricardo is a villain from Kinnikuman/Kid Muscle.
Born an Akugyō Chōjin, he was raised as a Seigi Chōjin Submission Artist in Brazil. His teacher, Pashango, discovered his evil past and attempted to kill Ricardo, but failed and ultimately lost his own life. So Ricardo continued to live under the guise of the Submission Artist, which is a very Robin Mask-looking choujin, with similar tights and a vest like Robin's armor and a helmet with a tinted visor over the face. Ricardo gained popularity in Brazil and eventually entered Brazil's preliminary tournament to be a Choujin Olympic representative. Ricardo's brutal style of fighting was not revered, as many other choujin fought in the same manner, which sheds quite a bit of light on just how nasty heroes can be towards one-another when it comes to glory. He defeats the Matenrō in this form during the first round of the actual tournament.
When his overbody eventually cracks open, his dMp roots are revealed and he turns into the "Lord of Darkness", a jaguar/piranha chojin who gleefully ignores the concepts of rules and mercy. At the Chōjin Olympics he is seconded by his friends Gazeman (ガンキュー Gankyū) and Pelé (ペレ). He defeats Jade in the quarter-finals, and then proceeds to lose to Mantarou in a semifinal match that involves a large, wooden structure covered with razor-sharp blades ("Punishment X", manga) or a similar device that confers electric shocks ("Electrolix", anime). Ricardo's policy in battle is simply to win. He has no desire to align himself with either good or evil choujin. Along with that, he seems to find deathmatches quite appealing, as he continued his attack on Jade even after the towel is thrown in. This don't lose, battle to the death, free agent kind of style seems to reflect properties from all three different factions of Akugyo Choujin. He has yet to make a second appearance.