* Do-Heun Chang and Kae-Lyn Kim die. Fuck, those two were my second and third favorite characters. They both had nothing but respect and love for Ken. So Boichi, being the asshole that either kills or violates the venerable characters such as them, did his dirty work.
* Yumin betrays and shoots Ken right as they are defeating the White Dragon Clan's head. Then, she claims to be the leader of the WDC.
* Ken survives with the help of Benito, and takes over the world during a timeskip. However, he hands everything over to Yumin through the Japanese reporter guy. Yumin and Ken never meet. They never marry and make kids. There is no happy ending for them.
* There is no happy ending, there is not even a coherent ending. Half of the Sun-Ken Rock Gang is dead, and Ken forgives Yumin because she 'repents'. Then Ken hands over the world to Yumin. The entire world: Americas, Europe, and Asia. No joke. What is this? I reiterate, they never get to see each other again.