The Man of Steel is not impervious to harm. He is weakened and will eventually die if exposed to Kryptonite - radioactive remnants of his old homeworld. He has no defense against magic and his mind will succumb to sufficient psionic assault, but his real vulnerability is his dependence on yellow solar radiation. Deprived of it, he becomes a mere mortal.
The Man of Steel is not impervious to harm. He is weakened and will eventually die if exposed to Kryptonite - radioactive remnants of his old homeworld. He has no defense against magic and his mind will succumb to sufficient psionic assault, but his real vulnerability is his dependence on yellow solar radiation. Deprived of it, he becomes a mere mortal.