This could prove to be a major win-win for both China, the region, and the US. Not Kim, however.
First of all, China could invade and conquer Nork quickly and secure any and all nuclear products and weapons. This would avoid the destruction of Seoul from the Norks massed artillery. Hopefully, China would have convinced several Nork generals to surrender quickly.
Now, if China gave some guarantees to the US ahead of time, and everybody soothed the Skors, some very good things could come out of this for everybody concerned.
First, China could set up a puppet government in Nork, then quickly pull back its armed forces. This would defuse the situation, both for the Skors and the US.
Then, this puppet government would begin immediate reunification talks with Skor. From this point on, China wins big.
By helping them to reunify, Korea becomes China's best friend in the whole world. Not only that, but they no longer have to fret about Nkor illegals entering China--in fact most Koreans living in China would be thrilled to go home.
Next, China gets a major trading partner worth billions to them every year. And there would actually be little reason for contention, from the Chinese point of view, because Korea already does things "the Chinese way"; so it is tolerable to have them on the border.
In other words, Korea would be much like Hong Kong and Macau in relation to China.
Being peacefully in the sphere of China, the US could gladly leave Korea, *saving* us billions of dollars every year, and still probably get an agreement that would allow us to park our ships in Pusan when they were passing by.
I'm sure that lots and lots of side deals would be part of the big package, such as Taiwan and Japan losing all interest in nuclear weapons again. But just about everywhere would be sweetness and light.
The universe would again be in balance.