The doctor's spirit infects Sam with extreme rage, causing him to turn against Dean and even shoot him with rock salt.
It blurs the lines between the game and reality, ultimately showing the house being burned to the ground (within the game or a new reality) to provide a sense of finality to that arc. [S1E7] Asylum
The ghost of Dr. Sanford Ellicott, the former head doctor who performed cruel "rage therapy" experiments on patients, is the primary threat. The doctor's spirit infects Sam with extreme rage,
Jude attempts to make amends for a past hit-and-run, only to discover the girl she thought she killed survived, causing a major psychological shift. American Horror Stories (Season 1, Episode 7: "Game Over") Episode 7: "Game Over")