Philosoraptor

Earth's sun gives superman his power, kryptonite are pieces of his home planet but I also never got why it kills him. Seems like it should only weaken or nullify the powers at the most.

Also, there are different types of kryptonite. They affect Superman because it moves the plot along.

Dammit :/ I know nothing about superman

uranium is pieces of Our Planet, and it kills us... and neither humans or Uranium need to be rocketed through space, exposed to 'unnatural environments, or be manipulated by Comic Book science...