>>281738600
>Chii enjoyed the master/disciple relationship and is lonely that Vivi "caught up" to her
>she is worried that Vivi might overdo it in her eagerness and push herself too much
>Vivi naturally achieved something great very easily, behavior that has greatly annoyed Chii in the past
Basically a perfect combo of stuff to frustrate Chii, and she's not exactly a particularly emotionally well balanced individual in the first place. It's pretty interesting that Vivi's idolization of Chii emphasizes how she always gets back up after losing and keeps going, but as the audience we know that pattern of losing took an extreme emotional toll on Chii.