I don't agree with those theories, because Kabr sacrificed everything that made him a guardian in the vault. his ghost: destroyed, his light: formed into the Aegis Shield, even his sanity was lost, but he regained it somehow, that being said, he did have no remembrance of who he was in his two guardian lifes (1 was consumed by darkness to help understand the vault, the other was consumed by darkness, but never died.). he walks along the vault, struggling to maintain a will to live against the impulses of his vex armor, now built into his brain, trying to find a way out of wherever the hell he is.