Before we go any further I'd like to clear out that I won't bring the powers from IV because that just came from the virtual reality/simulation. Throughout the series the protagonist survived occasions that would've been fatal to everyone else such as being shot, locked in the back of a car and left to drown, a boat explosion, being smashed from the top of a 7 floors building to the ground, freefalling in a tank from the top of the troposphere, and several other examples... the protagonist also has healing factor and can take much more damage than anyone else, gunshots that would've been fatal to others are just scratches to him... all of these things makes me believe that mutants/superhumans are very real from the start of the series and the protagonist is one of them. I also believe he was artificially created in a lab, possibly for a military and/or corporate project of supersoldiers, he possibly broke free from the lab slaughtering his way into freedom, the company responsible for his creation could be Ultor. What makes me believe that is the fact his past is barely brought, it's possible he also got his memories wiped out after he escaped. Other possible mutants: Victor Maero Gat Killbane it would be insteresting if Volition explored this concept a bit more, heck they could even release an Origins game explaining his past. I think it's interesting how the Protagonist could be turned into a 2/Portia Lee like character from Dark Matter Sy-Fy series.