The ending where Lucifer possesses Sarah is the canon ending.
Well, it states one of the 2 endings of the 2008 game is a Sequel Hook
If you noticed in the beginning of the game, Carnby is held captive. There is no explanation of how did it happen nor of how he got that scar on his left eye. Therefore, he's been sleeping the entire time for the entirety of the game, making all the characters representing himself.
- Crowley = Id
- Theophile Paddington = Ego
- Hermes = Super Ego
- Sarah Flores = Anima
- Lucifer = Shadow Archetype