I want to say something.
The game was scripted for Pandora to unseal Satella, Emilia remove Satella after the unseal, and Rem removing herself and Subarou after Satella dies.
Only way for this not to happen is
Pandora failing to find who has the Key.
Emilia dying DP4 or later after her Superbulletproof wears off.
Subarou being targeted with a kill between Satella being unsealed and Satella dying
The game was scripted for Pandora to unseal Satella, Emilia remove Satella after the unseal, and Rem removing herself and Subarou after Satella dies.
Only way for this not to happen is
Pandora failing to find who has the Key.
Emilia dying DP4 or later after her Superbulletproof wears off.
Subarou being targeted with a kill between Satella being unsealed and Satella dying