He was definitely abused and that was a flashback in a form of a nightmare. Not sure yet if he was beaten and tortured or r*ped. But he did suffer a huge trauma orchestrated by his father for some obscure reasons. He was also locked down at home during all his teen years until he became like a zombie from all the abuse and medication (remember that scary panel of him at the doctor with his hair down and his eyes all red?). A noble man called Lord Song is the one involved in this major trauma and it seems SH is still unable to face him. He is actually so broken that he numbs himself with sex, opium and tons of medicine all while giving up on any kind of healthy social behavior so his bad will be pissed. He barely resists suicide thoughts. He said in a previous chapter: "If I killed them all and myself, will that be easier?". So clearly, some people, including his father, did something really bad to him during his teens (︶︿︶)
why is nobody talking about seungho literally getting gangr*ped as a child