Mars is an Italian dMp operative who went undercover at the Hercules Factory posing as a mafia thug—a cover that worked until the dMp got destroyed and he had to actually enroll there. His real strength lies in psychological manipulation and an encyclopedic knowledge of Choujin wrestling technique and how to exploit it. He's technically an Akugyo Choujin (evil superhumanoid), but he's good at pretending to be a Seigi Choujin (righteous one).
His most significant connection is with Kevin Mask, dating back to their dMp training days when Mars saved his life. That history makes their later conflicts complicated—they're not exactly enemies, but they're definitely not aligned either.
After getting beaten by Mantaro, Mars dropped off the radar for a while. He resurfaced during the Demon Seed Arc playing the role of an Idol Choujin, which seemed like a genuine shift until the Ultimate Choujin Tag Arc happened. That's when his real priorities showed: he initially sided with the Idols to protect Kevin, but once things got going, his actual goal came to light—he wanted to steal the Completion Bulbs to resurrect the dMp and get back to business.
Content compiled by AnimeList.moe from publicly available sources.