Rose Tyler (Doctor Who)
In "Turn Left", when a Time Beetle causes Donna to change the past and change the universe, Rose continually appears to her and helps her to set things right by sending her back in time. She also gives Donna the message "Bad Wolf" to deliver to the Doctor, which tells him that it is the end of the universe. Rose is reunited with the Doctor in  "The Stolen Earth", but as the two run towards each other, the Doctor is shot down by a Dalek.  A sad Rose, reunited with Jack Harkness for the first time since she resurrected him in "The Parting of the Ways", is forced to watch the Doctor begin to regenerate again.