personal fav bl with good plots

Eight hundred years ago, the pure-blooded and noble Crown Prince, Xie Lian, was a well-regarded child of heaven with unlimited boundaries. However, who knew that after ascending, that his life would only go downhill.
Eight hundred years later, Xie Lian has ascended once again, but this time he has neither the followers nor any incense burned in his name. One day, on his way back from collecting trash, he picks up a mysterious youth and takes him home.

After a car accident, Taemin finds himself in the body of Siwon, a victim of bullying at school. No longer a pushover, he starts standing up for himself but then meets Woojin, an old friend from the past. Somehow, Woojin immediately picks up Taemin's 'scent' from Siwon. What happened between these two in the past and how will it affect their future?