man that's just a love story with an extra touch in action and "magic", after spoiling myself i barely remember the main plot. But in summary the whole drama looks like a generic soap opera on tv

. And i hate about the fact that there's always a victim in that kind of drama. And the new doppelganger girl is one of them (Fuck u SL2 tang san), but the main reason is because the author idea about love(?) makes a "harem ending" impossible and eventually qiu'er have to "died" in the end.
All of this based on wiki, and i never read the novel so it may be not really the case.