FROM DIFFERENT PEOPLE'S OPINIONS
At first I was confused, but thinking about it again I now understand. Here is what I think the writer was trying to achieve.
The writer wanted us to realize that Yi gak is in fact Tae yong and Tae yong is in fact Yi gak thus they always kept mentioning that Tae yong is Yi gak's reincarnation, but we just never had a better insight on Tae yong's character since he went into a coma which allowed Yi gak to come into the future.
You have to really think and connect all the loose ends before you make the conclusion that Yi gak is Tae yong. We would have to ask the "What if's" question.
First of all, Yi gak has never felt that way (LOVE) about Bu yong until it was her death that allowed him to go into the future and fall in love with Bakha who is a reincarnation of Bu yong, not having the memories. Yi gak may not know about the love that he could have had for Buyong if he didn’t travel into the future since it was always about the "crown princess". Also, Bakha could have met Tae yong which would have made it easier for them, but Taemu supposedly murder Tae yong changing their fate, thus allowed Yi gak to meet Bakha and let her experience that love in place.
Now, do you realize that it was their (Tae yong and Buyong’s) death that signifies the meaning of love that took place for Yi gak and Bakha. They may not even have the chance to know that they were meant for each other if their other counter lad did not experience "death" for them to transcend time to find love for one another. It’s confusing to understand, but you may have to reread my paragraphs again.
Yi gak’s riddle also ties closely with their relationship; you would have to die to live and live to die. Bu yong died, allowing Yi gak to love her 300 yrs later with Bakha who is very much alive. Tae yong got into a coma allowing Bakha to experience love with Yi gak who is pretty much just a historic person now. I believe that Tae yong is...