To those who are confused where the baby came from:
Spoiler!
In the novel, the baby was the child of the dëad woman who was in the place where LiQing went into hiding. He eventually adopted the baby
BL and EXO for life 
I give manhwa's spoilers from time to time
I give manhwa's spoilers from time to time
Spoiler!
https://tinyurl.com/4du7tebe
