illadelph12
aka Rakim Illa
Interesting Manjaro.
But it doesn't change anything.
It's still a biochemical process similar to photosynthesis. His body has specialized cells that metabolize energy like a plant metabolizes sunlight, and his body produces the radiant meta-protein that creates his biomatrix. That doesn't change the fact that Iceman can ride along and attack at the lines of Superman's own organic physiology.
He still metabolizes organic material, water, and air, he simply stores sunlight and radiation like we store fat.
The fact he can survive on his energy reserves is immaterial. A person can survive on their fat for a period of time as well. The only difference is that this part of Superman's "nutrition" is constantly restored due to sun and EM exposure. If you removed him from sunlight and other radiant energies he'd starve to death over time like any other organism without food.
Superman has a circulatory system:
You provided an example yourself that Lex used Supes own blood in cloning attempts. If Supes blood were protected by a biomatrix, Lex would not be able to manipulate it. That is portrayed by DC directly.
I'm sure we all know where I'm going by now, Ive already beaten this point to death.
Iceman simply has a tactical advantage. Supes is infinitely more powerful overall by comparison without question, Iceman simply has a trump card against him. He could remove all moisture from Supes body and cause dehydration down to the cellular level, halt the flow of bodily fluids throughout Supes body and cause cardiovascular, respritory, and cerebral seizure, or destroy Superman's brain from the inside along his blood vessels using moisture inversion.