Each time a Survivor is hooked for the first time, you gain a token.  Upon reaching 4 tokens Grim Embrace activates.

The Entity blocks all generators for 40 seconds.  The Obsessions aura is revealed to you for 5 seconds.

At the start of the Trial, 4 random Hooks are changed into Scourge Hooks:

The Auras of Scourge Hooks are revealed to you in white.
Each time a Survivor is unhooked from a Scourge Hook, the following effects apply:

The Auras of all other Survivors are revealed for 5/6/7 seconds.

The Auras of regressing Generators are highlighted in white.

If the Regression progress is interrupted on a Generator, its Aura will be highlighted in yellow for 8/12/16 seconds.
Surveillance increases the audible range of Survivors Generator-repairing noises by 8 meters.

Each time a Survivor is rescued from a Hook when you are at least 32 meters away, Make Your Choice activates:
The Rescuer screams and suffers from the Exposed Status Effect for the next 40/50/60 seconds.
Make Your Choice has a cooldown of 40/50/60 seconds.

Survivors within your Terror Radius suffer from inefficiency:

When using an Item, its Depletion rate is increased by 80/90/100 percent.

You become obsessed with one Survivor.
Each time you hit a Survivor other than your Obsession with a Basic Attack, Save the Best for Last gains 1 Token, up to a maximum of 8 Tokens:

Gain a stack-able 5 percent Cool-down reduction on successful attacks per Token, up to a maximum of 40 percent.
Each time you hit your Obsession with a Basic Attack, Save the Best for Last loses 4/3/2 Tokens.

When the Obsession is sacrificed or killed, you can neither gain nor lose any more Tokens.
You can only be obsessed with one Survivor at a time.