Kurtz is made to seem like a "god" to everyone because he tells them what to do & they don't speak, but only listen. He let the greed take over him from wanting to do what was best for the Congo to becoming a dead man who thought the Company should "exterminate all the brutes". Kurtz doesn't care how he is perceived, his mind is simply on all of the ivory. He fails to realize he's not making his situation nor his journey any better. I believe that he became extremely ill as a punishment for his "darkness".