Poong woon died

Why does he have to die , interesting storyline, great movie , I love it and I cried , but I just wish their love was happily ever after but he had to die and they didn’t show us how he died or even say what happened to him ??? ?????????????????????????????? I wish he was lost or something and there’s a part two of him regaining his memory and not him dying just like that , what’s the point then ??‍♀️