Head, rifle, and backpack - ARAH Sci-Fi
Upper torso - 25th Major Bludd
Lower torso, upper legs, and arms - 25th BAT
Lower legs - 25th Wraith
Pistol - 25th Iron Grenadier

As a kid I disliked the GI Joe storyline, as I never read the comics and had only seen the cheesy cartoon, but I loved the figures. So I created my own story. In my universe Destro was king of most the post apocalyptic planet Earth. One of his most powerful foes was Croc Master, who had super-human strength. To deal with this problem Destro had his brightest engineers design cybernetic systems to enhance a volunteer who would become the ultimate mecha-warrior to defeat Croc Master and his band of genetically enhanced comrades that defended Australia and many of the South Pacific Islands.
As Destro's engineers began their task he searched the ranks of his Iron Grenadiers for a volunteer. It had to be one who possessed leadership skills and was a loyal soldier. As if put in place by fate, about the time that the engineers had designed a well functioning system, an Iron Grenadier Lieutenant was attacked by several of Croc Masters pets. In spite of the IG armor, the young Lieutenant was on the brink of death. The crocs had torn off his arms and legs and had severely maimed his remaining body. He was offered a chance to become whole again. Not just whole, but super-humanly powerful. His mechanical limbs, electronic implants, and armor for his remaining humanity were made from an ultra-hard, yet light weight titanium alloy. It was even used to reinforce his remaining bone structure. He was also injected with performance-enhancing muscle amplifying chemicals to make his remaining living tissue strong and durable. He's like something out of a comic book or movie, a "Sci-Fi" comic or movie. Therefore deemed Sci-Fi by Destro.