from my understanding the first timeline took place in the joseon dynasty. the second timeline is prior to or midst the korean war (south vs north). the third is modern time. it is most likely that sungyeon was reincarnated in the same household but in different eras and all of which as basically his ancestors. hoseok on the other hand died in the first timeline and only got reincarnated in the third.
from my understanding the first timeline took place in the joseon dynasty. the second timeline is prior to or midst the korean war (south vs north). the third is modern time. it is most likely that sungyeon was reincarnated in the same household but in different eras and all of which as basically his ancestors. hoseok on the other hand died in the first timeline and only got reincarnated in the third.