I can picture a scene at the Keyblade Graveyard where Sora would be "possessed" by Vanitas (assuming he is one of the thirteen darknesses, which is likely in my opinion), similar to how Ventus got possessed in BBS. Next, Kairi would have to fight Sora, similar to how Aqua fought Venitas, and then saves him from the darkness (like how she did in KH1). What do you guys think?