I was thinking about something yesterday. You know, of the three All-Stars, Jack had his story, back in Zou, and Queen had his story in Udon prison. What story did King have, before the raid? Shoving Big Mom's ship off the waterfall? He kept being mysterious throughout the Ark, with Oda dropping us hint after hint, exposing his face at the same chapter he's defeated.
I remember reading in one of the SBS'es, that Oda was asked why he drew the enemies so ugly. His answer was that he hated them so much. Now he drew King as one of the most hansome characters in One Piece. Could it be that Oda doesn't hate him? That he plans something more for him in the future? There have been other characters who started out as enemies and ended up helping Luffy, two of them even joined the Straw Hats (Robin and Franky). And King believes in Joy Boy. Although he denied it to Kaido, I think Kaido still suspects that if the real Joy Boy shows up, King might follow him. I Think that was the reason why he mentioned Joy Boy to Luffy, saying he's not him either.
King still has an untold story, that's why I think, and hope, that we will meet him again in the future. Will you hold your fingers crossed with me?