I want to create theory that the real sibuxiang still alive but I can't think any 😭😭😭😭
There is a great way!
The heavens always lie, my theory is that this memory could also be false!
Remember that the chapters follow it made it so that bixie seems to also have altered memories, or does he?
The gods would have been careful, and carefulness would also lead to maybe also altered Sibuxiang memories and body just incase he decide to not follow the gods order
Tianlu never mentioned how exactly Sibuxiang died, nor does bixue think that Sibuxiang is dead, also Sibuxiang don't know how he died himself, even though to truly make the deer spirit seem like Sibuxiang they would put his memories, if the heavens altered Sibuxiang memories, this would explain the difference in personalities. So maybe they will reveal that instead of the deer spirit becoming Sibuxiang they would reveal that Sibuxiang after being greatly injured was instead revived using the parts of a deer. And not the deer spirit getting the bones of Sibuxiang. This part would explain the difference in fur colour. The mask would actually reveal the qilin Sibuxiang colour to not make tianlu remember.