1. Terra, (in his return, maybe that he had a another guardian of light that will let him return to fight back with Sora and have revenge with Master Xehanort).
2. Lea, (he, too, have the power to wield a keyblade that he fought for the light with Sora, and also, he'll fight with his lost best friend Isa about their friendship was about to end already).
3. Roxas, (maybe in his return had been desired, another members of guardians of light, with two keyblades, continued with the problems with the Organization XIII for revenge for Xion's death).
4. Xion, (like Sora and Roxas, she had the power to wield a keyblade and been hint she will return with the power of light, she'll reunited with Axel and Roxas after the Organization was destroyed).
5. Namine, (Namine's ability to have the keyblade to wield it's power, in her return, she will fight with her own keyblade to wield it).
6. Yen Sid, (he'll join the fight with Sora as a leader of guardians of light and show them the power of light with his powerful keyblade and fight with his apprentice Xehanort).
7. Eraqus, (until his return, it reveals that his heart was inside Terra's body for safe keeping, and he'll fight back with Master Xehanort for revenge).