generally body mutations like this happen with twin fetuses, when one absorbed the other. If I am remembering correctly radiation does have something to do with abnormalities like this...
honestly im not sure about the translation quality itself since i dont read chinese but your english/typesetting etc is very easy on the eye's and is nice to read so keep up the good work.
Aw man, it'll break my heart when little Ji gets rejected. He's actually a good guy and he has a terrible childhood. That's enough to make me sympathize with him 😢