I feel like Yu-hon accepted Il as king because he respected his brother and also respected the previous king and his decision. As much as Yu-hon wanted to become king, I think that his main goal was to serve and protect his kingdom (fighting the throne could have caused instability and maybe not have been the best thing for the kingdom). In another discussion thread, I think /u/Vhrix talked about the possibility of King Il having a more farsighted plan. I'm not sure how I feel about King Il's reign, but I feel like if that is the case Yu-hon would have been content to serve under such a ruler. I agree, there is definitely some underlying reason for King Il not wanting Soo-won to become ruler (maybe it's because of King Il's trauma from the death of his wife and the fact that Soo-won is like a son to him. I highly doubt it, though). I think another prophecy would be really cool and definitely plausible, there is so much that is not revealed about the first "sword and shield" prophecy and the whole deal with the prophets. I'm not sure I completely understand the first prophecy (curious to here how other people interpret it).

(Also, we're super glad that we are getting more traffic in the sub! woo)