@copperhead
"The worst peace is better than the best war."
There have been three wars since Soo-won began his reign by usurping the throne. Maybe we can ask the people of Sen Province what they think of it. (Oh, wait, we know that already.) Or the families of the dead soldiers.
Soo-won only seems a good leader because his side won, but it could've easily been the other way round. Not to mention the fact that Yona beat him to most of these events by finding out what was going on before he ever did and being instrumental in solving the problems. And she was the one who avoided a particularly bloody war with Xing, a war that would not have happened hadn't Soo-won usurped the throne.
Doing the wrong thing (betraying others) for the right reasons (supposedly setting the country in the right course) is quite the slippery slope. Because the means remain after the deed is done. If Soo-won betrayed his king, what's to say he can be trusted, say, in future dealings with the other countries? He reneged on an international treaty with the Kai Empire just because he happened to be in a position of strength. Do you think the Kai Empire, or the other countries, will be able to consider Soo-won a good faith partner?
King Il, whichever his faults, preserved the peace of Kouka Kingdom. His domestic policy might have been lousy, but it seems to be predicated on preventing war, probably as a consequence of
Yu-hon's bloodthirsty wars in the previous reign. In fact, the Xing episode is almost certainly the reason why King Joo-nam decided Yu-hon was damaged goods and too violent to lead the country. Yona said so, and she's probably right. In fact, we still don't know the truth behind Yu-hon's assassination on Il's orders, or even by Il. My guess: Yu-hon was either plotting against Il, or became so belligerent he became a danger to the realm. I also bet Soo-won knows, but cannot accept that, and won't revise his notions about his father, unlike Yona, who's coming to terms with Il's shortcomings since she began her journey.
I can't stand bumbling militarists like Geun-tae, who sat in his palace and blamed all of HIS tribe's problems on the King, when Kouka is a confederation and the generals have administrative powers over their own realms. It appears that lots of Kouka's domestic problems were as much due to the generals as to Il's policies, if not more. Need I remind you that the one who did the most for the Fire Tribe was Yona, by discovering the Iza seed?
It's easy to praise Soo-won by winning wars unleashed as a consequence of his actions. But I don't buy that. And Hak was right: if this was a policy problem, Soo-won had more than enough means and skills to persuade his uncle.
Soo-won deserves to hang not only for being a traitor, but for being an aggressive leader who thinks war is the way to solve things. Without Yona, Kouka would've been plunged into warfare long ago.
He may be an improvement on his father, but he still thinks Yu-hon's actions were justified. But Yona is an improvement on HER father: compassionate, strong, wise, and with peace as her main concern. She has the right to that throne and that crown, and she can't seize them from the usurper soon enough.
And let Soo-won's body hit the floor.