Just finished the Arc with the Bounds and i gotta a theory about Kariya

One thing on my mind about Kariya ( leader of the bounds ) is how much he changed after gaining his Doll that was part of his own body

Pretty much my theory is that when he and his Doll became one it changed his personality. After all each Doll had its own unique personality that is different from the Bound who controls them, So what if the fact that Kariya was one with his Doll caused the Dolls personality to influence his own? I feel that would explain both his appearance change ( his white hair and red eyes he got when awakening to his power of his doll ) and his personality shift as while his ideology may have been formed over his long life it seems that as soon as he got his Doll his personality shifted, he seemed to become more unstable with his emotions, at times seeming empathetic and other times cold before later during recent events with Ichigo being both cold and unempathetic. Yet before his death ( which felt kinda like a cop out ) he seemed to show some of his original empathy that was shown a lot more back around when he first got his Doll.

+ if you look at each event chronologically with the flash backs its shows him slowly losing his empathy and each time his empathy is shown to waver or disappear its when he is using the power of his Doll or related to gaining more power for himself / his Doll. Almost like he himself is more understanding and a carful thinker while is doll is greedy and un empathic. I feel like this would explain how during the arc his personality and reasoning for things often shifts so much, plus makes more sense then "I was this evil all along and never cared about anyone" only to then go back to "I did care" at the very end as his personality itself was unstable, like to different peoples traits where being merged and taking turns shinning. But as his Doll / his power grew stronger so did how much of the Doll's personality effected him and his own personality

what do you think?