When Sora sacrifices himself to save Kairi, he passes on the Keyblade to her.
Meaning Sora doesn’t come back, and Kairi becomes the new protagonist.
Since Sora doesn’t come back, there isn’t any reason to take Roxas away from the Organization. Xion would still exist since Kairi would be the one sleeping. And since her most precious memories would be of Sora, Xion would take the form of a boy with black spiky hair.
Riku doesn’t need to go all darkness to convince Xion to return to Kairi. He retains his original form and maybe even travels with Kairi when she wakes up.
Axel never defects from the Organization since Roxas is still there. Roxas feels a connection to Riku and Kairi because of Sora, which he confesses to Axel. Maybe they both defect together then, since Axel would be smart enough to know Riku and Kairi are gonna take the whole Organization down.
Riku doesn’t trust Roxas, but Kairi does because she looks at him and immediately thinks of Sora
I’m just spit balling ideas, feel free to join in and add more so we can all suffer
happy summer everyone! i like to think that Kairi was the track star of the group, thus smoking the other two consistently when they raced on the beach