Super Hero And All Round Good Guy
The original time sequence, he had kidneys when he went through the space station visit. Then they went back in time and removed his kidneys before the doctor could take them, thus creating an alternative reality where the doctor removing them could not of done so as he had none. Meaning that they destroyed reality and are now living in an alternative dimension where a doctor from another dimension removed his kidneys requiring him to steal his kidneys from his past self who is also in this alternative reality. I need a lie down.