Chang Ge's real father [THEORY]
There is a huge possibility that changge is li shimin's daughter.. remember in the prologue, where li shimin asked changge's mother why did she marry his 1st brother?? maybe she was already pregnant with li shimin's daughter that time.. but since shimin was far away from battle, and it was a taboo to be pregnant without a husband that time, maybe that is the reason why she immediately married the crown prince. to hide her and shimins child.
also remember when it was mentioned that changge really love her shimin uncle.. maybe that was actually her love for her real dad showing without her knowing
