I feel its much more likeyly that Hak is The kings son, especially if Yona was adopted (for being the reincarnation). Because the king favored hak in the beginning. Also the king was pushing for Yona and Hak to marry even when she was in love with soowon. If Hak and soowon where brothers why would the king be against soowon but not hak? Also Yona being adopted would explain why she was treated like a prized jewel in the beginning. didnt the king have plans for her to marry hak? that way his bloodline/direct decendant would still rule. Hak was prob given to wind tribe to protect if he was direct decendant.
I feel its much more likeyly that Hak is The kings son, especially if Yona was adopted (for being the reincarnation). Because the king favored hak in the beginning. Also the king was pushing for Yona and Hak to marry even when she was in love with soowon. If Hak and soowon where brothers why would the king be against soowon but not hak?
Also Yona being adopted would explain why she was treated like a prized jewel in the beginning. didnt the king have plans for her to marry hak? that way his bloodline/direct decendant would still rule. Hak was prob given to wind tribe to protect if he was direct decendant.
Thats just what i think anyway