Their pharmaceutical company was basically doing experiments on him to see if he could become an omega? I think that's what it is, but since it didn't work in their minds or possibly at all, he was put through a lot of abuse and at the moment, the company boss is using that to their advantage of no one knowing so he's having his actual son pretend to be Han and get married. The prince didn't know this though, so he just realized that he is the real Han. He does have some characteristics as we can see, but they haven't made it clear what he is.
He was normal, and he was a part of an experiment with a bunch of other children, they would give them meds and do all sorts of tests, and uke was the only survivor with any kind of omega characteristic development, but then, the uke stopped showing any signs of improvement for the experiment but because they spent a lot of money on research, they didn't want to stop, so they continued, and as for the uke's backstory, he doesn't remember his name nor his parents so he was given that name by the scientists, and the leader of the research had a son, but never showed him nor the uke, and he always kept saying how his son is an omega, that's why the uke's name was given to the son, and their plan is, after the uke becomes a full omega, they will take his blood samples to turn the director's son into an omega so that he marries the Prince (alpha)
k so he has to like pretend to b some else n his real name is the one that he’s responding to rn but like???? i dont rlly understand why he was given a different identity and with the whole omega thing like does he naturally have omega characteristics or was he sorta made like that bc of some illegal drugs or something??? IDK IM SO CONFUSED HELP