(No auto-claim with the ancestors. This only gives you what your character needs to be in order for it. Otherwise, what the questions answer will be.)

Sora-Keyblade wielder/Pure light control
Riku-Keyblade wielder/dark and light control
Kairi-Keyblade wielder/Pure Light
Roxas-Keyblade wielder/dual keyblade wielder/Dark and light Control
Namine-Nobody/Memmory control
King Mickey-Keyblade wielder(no they aren't related. only one person thoughwlecome chippy ^^)
Xion-Keyblade wielder/Light control
Terra-Keyblade wielder/Dark control
Aqua-Keyblade wielder/Light control
Ventus-Keyblade wielder/Pure Light control
Vanitas-Dark Keyblade wielder/Unversed control
Master Xehanort-Dark Keyblade wielder/Pure darkness control

Below have to be Nobodies in order for them to be the ancestor

Xemnas-Nothing control
Xigbar-Space control
Xaldin-Wind control
Vexen-Ice control
Lexaus-Earth control
Zexion-Illusion control
Saix-Moon control
Axel-Fire control
Demy-Water control
Marluxia-Flower control
Larxene-Lightning control