。
Because in this world, there's nothing but villains and hypocrites.
Literal
Because this world [in-には] villain [and-と] hypocrite [only-しか] not-exist [feminine-のよ].
だって 'because / I mean' at the start is the casual explanatory opener, often used when justifying a bleak or emotional claim. この世 'this world / this life' contrasts with あの世 'the next world / afterlife.' ~しか~ない is the restrictive 'nothing but X' frame, where the predicate must be negative. のよ is the feminine explanatory-emphatic ending. A gloomy, cynical one-liner built on stock idioms.