Responses
it was already established to the reader not to Nike
I bet it has to do with how he wrenched power away from those was responsible for his father and mother's fates. As well as the revenge he and his uncle perpetrated.
I think Nike would understand because she knows something bad happened to Livi in the past and that there is still enemies they need to be aware of.
What did levi do that he doesn't want Niki to know about? I mean it's already established that he was kinda brutal before he met her.