Ah, interesting. The pregnancy and the creation of life by the human body and the death of the parents of little Ethan is presented as a retrospective: Very beautiful. And very understandable. The reader himself must now fill the gap with his imagination and ask himself: "Then the whole thing was a failed experiment and what happened there on Decatur cost life, which in turn made life possible down there on earth? So what might have gone wrong with the takeover of Yoh?
You don't explain what one should understand or realize, because it lies beyond explanations.