|Encountered in:||Chapter 8 conclusion.|
About the BossAfter finishing writing the book in any of the bad endings, Simon shoots himself in the head and Book Simon (the protagonist) is sent into a nightmare world (his own mind); the realm bloodied and constantly changing, with countless book pages with "Suicide" written on it. Book Simon will proceed to make his way through the warped world and eventually climb to where Sick Simon resides - a depiction of what is left of the real Simon, attempting to fight away his evil twin. It can be presumed that the fight itself is a depiction of Simon's actions eventually overwhelming him, driving him to commit suicide.
The fight against Sick Simon is possible, but potentially difficult for those who do not know what to do. Simon will sit out of reach behind several steel bars, gunshots having no effect on him. Simon will use psychokinetic powers to throw items at the player, forcing them to time their jumps and crouches just right to avoid them.
The player will also have to fight four hordes of unique Faceless, one of the creatures within the horde being a unique variant that will drop a Valve upon death. Four valves must be collected and then used in separate corners to raise the bars blocking the player from reaching Simon.
Upon finally raising the bars, Book Simon will enter the room and proceed to mercilessly beat the real Simon unconscious before strangling him to death. The death of Sick Simon results in Book Simon collapsing as well, the conclusion of the battle causing the real Simon to give in and commit suicide. In the 4th ending of the game, Sick Simon is a playable character.
Relevance to Simon
The area where he is to be found and fought is constantly changing, with corridors twisting unexpectedly. This could be symbolic of Simon's current mental state, as he has embraced depression and insanity and the sudden mood changes that come with it. This is also seen when Book Simon must climb many books that are used as platforms, possibly meaning how Simon's book was his ascension to insanity and suicide. Being able to damage with his mind at a depiction of himself could mean how Simon's mind has been damaging him in real life due to his mental illness. The fact that he's behind bars could also mean how he has locked himself away in his mind from everyone else.
- The wheelchair that Sick Simon has is a recycled portion of the Wheelchair Twitcher's model (an enemy in Afraid of Monsters).
- Sick Simon seems to be smiling as he dies.