You will have to run or evade everything. You have to kill only one enemy as Barry, the Cabin Revenant. All others enemies are secondary. The following actions will ruin your attempt: Finish, melee attack, or stealth attack even if you use the knife. Using a throwing item, Molotov cocktail, explosive, brick, or smoke. While playing with your alternate character, do not use any abilities that interacts with an enemy (for example, using a lamp as an "aimed" flashlight to blind an opponent with Moira.

The following actions are acceptable.

Using a flamethrower statue.
If Clair or Barry shoots while you are playing as Moira or Natalia.
Break the lock with a brick melee attack (as Natalia, forest path).
Killing zombies and revenants with only knife attacks.

Select the easy difficulty setting. Collect Herb beforehand. When you have to evade many revenants as Barry, switch to Natalia. Because revenants cannot grab Natalia, this becomes useful at the end of the chapter.