Shaddow used to be a scientist at a NASA Space Station Lab, and because he was required to work in zero gravity conditions, the program required that he resistance trained everyday to prevent muscle atrophy.
A biochem company wanted to test out a new serum that would keep skeletal muscle in a steady hypetrophic state to extend the body's ability to perform extended missions in space, but rather then growing in size, the muscles grew in density as to prevent the muscle from outgrowing the spacesuits or severely altering the aesthetics of the scientists. Only 5ml was required to achieve this steady hypertrophic density state for 72 hours.
Shaddow brings his on-the-go, liquid Whey protein with him to work Invalid Link Removed
A hater at the space station wanted to off Shaddow because he kept hogging the attention of the female scientists, so he filled Shaddows entire liquid whey protein with this serum, in hopes that it would kill him, or at least keep him away from work long enough to get himself some female scientist chicken heads.
Following a normal training session, Shaddow downs his liquid whey, which was actually filled with the special serum. However, he ingested over 100x's the allotted amount of this serum and fell to the ground. He felt his body becoming harder and harder, until his muscles became so dense, that it was like steel, and this became a permanent effect because his system was so overwhelmed and over-saturated.
The only thing that can kill Shaddow is swimming, he's too damn heavy to float, and that strange Pentagram of veins in his forearms, which will be revealed later.