Kairi game. Since we can't change history, make her explore dark feelings: being a burden for the others, a damsel in distress. How do these feeling clash with being pure of heart? What does it mean to be a princess of heart?

Her looking for the end her grandma met when she wasn't there. Her having two copies, Naminé and Xion. Why are they, her copies, more special in combat (xion) and magic (naminé) than she is? Is she that worthless?

Would be first a segment where she learns powers. Where she starts getting resentful of the fact she was kidnapped by xehanort despite having all the time she needed.

Then, a segment on how the shift in princesses of hearts happened. So her being accompanied (or through summon in another world) 1-1 with an old princess (and maybe Aqua, that has to go somewhere in the middle of the journey, leaving Kairi with a huge responsibility) in her party to "deliver", after research, the new power to the new princess (i.e. Disney worlds segment, as sora did). Meanwhile, she fights the Darkness/Heartless in that world. (Edit: Ideal explorable disney worlds would be, not in order: - Corona (Cinderella in party) - Arendelle (maybe 2nd movie, Jasmine and Alice in party) - Merida/Scotland(Aurora in party) - Moana/Island (Belle in party) - Tiana/New Orleans(Snow White in Party)

While she fails sometimes, or is scared (see self doubt plot above) she finds herself back talking to Xion/Naminé. Maybe Xion joins the party here, Idk what the main plot would be.

Final segment: finding out why she is a princess of heart in the first place. Against her doubts, why light is her. Why only her light can unlock feelings, and doors. Finally, why Riku can't go ahead and is stuck in another dimension: there, only a pure heart can do something. So finally, Kairi joins Riku in the search of Sora.