The “Fight Demons” achievement requires players to choose to stay on the island during the ending of Sons of the Forest. The player must turn around and pick up their backpack to unlock the achievement.
The Ending
The Sons of the Forest ending is a cutscene that involves Timmy, Eric (the protagonist in the first game), the person wearing a silver jacket, the player, Kelvin, and Virginia.
During the second sequence of the ending, the player will have a choice of whether to leave the island with Eric and Timmy or stay. Choosing to stay will unlock the “Fight Demons” achievement.
To stay, the player must turn around and retrieve their backpack which is marked in yellow.
