@YapperWhenIGetTheChanceTo i think since rezefs childhood was lonely because he was called an illegitimate child from the beginning he began to obsess over the throne to kind of "prove" everyone that he deserved it. But other than caneya he never had anyone to depend on which is why he developed such a bad and cruel personality. Caneya on the other hand had a nanny she grew up with but her only person to depend on was expelled from the capital. In the end her personality changed to an attention-seeking type, easy to manipulate and in search of someone she could depend on and trust. She wasnt an illegitimate child like rezef so she didnt have to fight to be accepted but ig she was just really lonely. 
well this is a bit long but this is just how understood😓😓 feel free to correct me if somethings wrong🙂↕️

I can understand why the original Caneya grew up with a bad personality. She's the same as Zeref, ex...