Hello! You make some interesting points, but there are several places where I would have to respectfully disagree with you regarding Soo-won’s character. Warning: Mini-essay coming up...
Whether or not there is forgiveness in store for Soo-won, the author has always shown us multiple sides of her characters. I think her main goal in showing Soo-won’s story is to show us that he, like everyone else in this story, is a human being. Seeing Soo-won’s story along side Yona’s is an exercise in empathy/sympathy. It’s easy to paint a character as a villain or view them in the light of some single defining characteristic, but it’s important to understand that these characters are so much more complex than that. People are not morally absolute and I think that the author does an excellent job in demonstrating this through her characters.
REGARDING SOO-WON’S KILLING OF KING IL: I do agree that Soo-won killing King Il was primarily motivated by revenge. I sincerely believe that Soo-won becoming king was good for the country, but it is almost certain that it being “what was best for the country” was an afterthought. So yes, in that sense, Soo-won killing King Il was not motivated by “good” intentions, and yes, I will agree that in doing so, Soo-won betrayed Yona and Hak. Absolutely, he made a decision that was perhaps not the best decision he could make at the time. But it’s important to realize that Soo-won is very much a human character, and humans make terrible mistakes. To say that it was because of his ego and cowardice is a bit of an overreaching statement. Even if it was motivated by revenge, Soo-won did not kill King Il out of some sort of inflated ego, or some desire to prove that he was the best. Soo-won is simply a son who cannot forgive the man who killed his father. Even if King Il had a reason to kill Yu-hon, I strongly believe that Soo-won would not have been aware of that reason. He is just someone (a child, in fact! remember that Soo-won was only nine when his father died) who had his father taken away from him by his uncle, a man he trusted and loved. And every time after that he saw King Il, all he would see was the face of someone who killed the man he respected and loved the most in the world. It’s easy to see why Soo-won would have harbored such resentment for King Il, if this were the case. I also very strongly disagree with the statement that Soo-won is a coward, as I believe he is one of the most courageous characters in Akatsuki no Yona. Soo-won knew that by killing King Il, he faced the risk of many of the people that were essentially his family (Yona, Hak, Mundok) turning their back on him. How terrifying must it have been to know that by avenging his father, he would be losing the only people of his family he had left? And isn’t that what courage is? Facing the things that frighten us most in order to do what we believe is right or necessary? It might not have been the best decision, as I have said before, but that does not detract from Soo-won’s courage in making that decision.
Regarding Soo-won simply marrying Yona to take the throne, I do not believe King Il would have allowed it to happen. King Il was vehemently opposed to Soo-won marrying Yona and becoming king, if we recall. Of course, we don’t know exactly why, but I believe it has something to do with the his killing Yu-hon. He told Yona that he would accept ANYONE but Soo-won; that hardly seems like a statement from someone who would simply roll over and listen to whatever the four tribes told him. So marrying Yona was basically out. Not that it matters, of course, since we’ve already established that Soo-won was primarily motivated by revenge, but even if he wasn’t…
Did Soo-won make the right decision to kill King Il? Probably not. Was there a better decision that he could have taken? Perhaps, but it isn’t something as obvious as marrying Yona. But does his decision make him an egotistical coward? No, I don’t think so. Misguided, perhaps, and certainly flawed. But human; above all, Soo-won is human, and I think it’s important to remember that.
REGARDING SOO-WON AS A KING: Yes, it is the king’s responsibility to protect the people. However, this is hardly an easy task. If this were the case, King Il -- and every other king for that matter -- would have been a more effective king. Soo-won did the best he could with the resources he had to protect his people. Any looted villages would not have been Soo-won’s failure but rather an unforeseen casualty. Because that’s the thing: casualties are a very real part of war. You cannot always protect everyone, but you can certainly try to protect as many people as possible. That is what Soo-won did. Please don’t overlook the lives that he was able to save.
Furthermore, while he could have chosen to send at least one troop to each village, this would have divided his forces and reduced the fighting power in the locations that would be critical in deciding the outcome of the war. If certain cities were to fall, the kingdom of Kouka would fall. Choosing to concentrate his forces in critical locations was a strategically sound decision. Wars are often long campaigns. Thus it is absolutely important to have as many advantages as possible. Forces that are spread too thinly would be easy picking for a much larger army, regardless of how skilled your warriors are. Yes, he made his decisions to win, but isn’t winning a critical part of fighting a war? He did not make his decisions to “look good.”
Finally, throughout the series, the author has shown us many times in which Soo-won has acted with his people’s best interest in mind. For instance, he went to Awa to investigate the rumors of Yang Kum-ji’s corruption. He simply could have turned a blind eye to this, or sent someone else, but he went to verify this himself. Upon arriving at Awa, he learned that the pirates had already taken care of Kum-ji. Instead of punishing the pirates for… well, piracy… he chose to overlook it since their actions had protected the villagers of Awa from Kum-ji’s greed, which is what he had intended to do himself. Also, in his visit to the Earth Tribe, his seemingly meaningless actions were intended to revitalize the Earth Tribe’s failing economy. An incompetent king would not have been able to do something like that.
Ultimately, while I am hesitant to forgive Soo-won for betraying Yona and Hak, he certainly has my respect as a king and a commander.
tl;dr: Soo-won is human, and humans make mistakes. He has made bad decisions, but that does not make him a bad person, nor does it make him a bad king.