Nick told Juliette it was his fault. Why would he say such a thing? It sounds like he feels like he's guilty, but he never says why he feels he's at fault.
Maybe he feels he's a fault because now that she's a hexenbiest, he can't stand her?
Maybe he feels he's a fault because now that she's a hexenbiest, he can't stand her?
The best way to frustrate a cyberbully is to ignore him.