Considering other cultivation-thingy (manga/novel) I've read, I found it quite surprising how quickly he decided to still be connected with A-Ting. Usually, cultivator's main object is to ascend, and they get less and less worldly to reach that. Blood-related family actually rarely mattered in most stories. Even more so considering cultivation in this one reach this level of controlling element etc. Other contact usually only concerned other fellow cultivators, their master, or fella in one 'school'. Thus why I found it quite surprising that he actually quickly decided not to sever contact with A-Ting when he learnt that A-Ting is his sister, even more so when their point of contact actually located in that soul thing that might hinder his cultivation development.