My first OC that i implemented in a roleplay was a mutant living in in a sci-fi city's slums, earning money as a deathmatch fighter. Snide, punkish and rather cunning. He wasn't overpowered, surprisingly, having no more than an accelerated metabolism, and a well balanced mind control ability - not too much compared to the gun toting nazi cyborgs and a despotic government's superpowered soldiers that together were the main antagonists. He was a sneaky bastard though, never meant to get caught by any of them. XD