Captain Hero was actually a child named Bobby Wright who was abandoned by his teenage mother before he was 6 months old. He then became a ward of the courts. He became a runaway and it was during one of these times in which he encountered a meteorite which had fallen in to a field that he was crossing. When Bobby tried to pick up the meteorite he was infected with an unknown alien spore that altered his atomic structure.
Mayor Story Arcs
Captain Hero is born
The young boy had just received super natural powers and as such wanted nothing more than to become a superhero. Bobby had the ability to alter the shape and density of his molecular structure as well as the structure of anything around him. So first he changed his appearance, looking somewhat like Captain Marvel and Captain America in the same body he went on to use his powers similar to superman but unfortunately he did not have the emotional strength for his abilities. Reacting before thinking was his flaw, e.g.; he initially goes to Power Man and Iron Fist and asks to become a hero with them in their Heroes for Hire, but after he is declined the boy in the hero re-emerges and he goes off in a destructive tantrum.
Another major obstacle for the boy was that the alien spore that had given him his power was also killing him. Upon hearing the boy's problem Power Man and Iron Fist took a shining to the boy even though he had caused immense problems. Power Man and Iron Fist helped doctors to look after the boy as they searched for a cure. He eventually went to live at Project Pegasus. He had some interesting times during his short career, fighting a demon and meeting the Beyonder.
Death of Iron Fist
The final issue of the Power Man and Iron Fist series (no. 125) sees the death of Iron Fist by the hands of Captain Hero. Iron Fist learns that the boy Bobby Wright's health has taken a turn for the worst and it seems he only has a short time of life left. Iron Fist rushes to the hospital to help the boy and administers healing via his chi. Upon feeling he has helped all that he can Iron Fist sleeps as the ordeal has been very draining. At this time the boy awakes in pain and transforms into Captain Hero and attacks the sleeping Iron Fist, killing him in the process.
It was later revealed, in the pages of Namor, that Captain Hero was actually the Super-Skrull. He had been dying of a disease (like Bobby) and had been turned into radiation, where he orbited the Earth. Master Khan, an enemy of Iron Fist, brought him back to Earth and told him he would cure him if he worked for Khan. The Super-Skrull agreed, and Khan turned him into Captain Hero, erasing his memories so that he truly believed himself to be Bobby Wright.
Khan even turned himself into Bobby's guardian so he seemed to have a full, everyday life. However, when Captain Hero killed Iron Fist, the joke was on Khan, because the H'ylthri, a plant race from K'un-Lun, was also trying to get at Iron Fist. They had captured him and replaced him with a plant simulacrum. Therefore Captain Hero only killed this plant version of Iron Fist. Khan eventually double-crossed Super-Skrull and sent him back into orbit.
None of this was at all apparent during Captain Hero's life.
Captain Hero possessed superhuman strength and durability. He could fly. He could turn invisible and intangible. He could supposedly control all the molecules of his body. Most of these powers can be explained through the Super-Skrull's own powers, but Master Khan must have added some of them, such as intangibility.