
My guess is, much like the ending to Harry Potter, 11 is going to need to sacrifice herself in order to officially end whatever it is that is doing all this. Like Harry was connected to Voldemort, 11 is probably connected to this main monster.
So in order to officially kill it and put an end to all of this, 11 will need to give the ultimate sacrifice. Herself.
So in order to officially kill it and put an end to all of this, 11 will need to give the ultimate sacrifice. Herself.