I think xiang lun goes back in time to prevent xiao yu from
dying...cos during the first run, xiao yu already died from her
asthma because she was too agitated and no one was nearby her...but
if xiang lun could with her all the time to take care of her, she
wouldn't have died so young....
so basically xiang lun went back to rewrite his own destiny and
hers...
dunno why this show reminds me of butterfly effects...