Performing the Damage Generator Action on a Generator activates Trail of Torment:

Grants the Undetectable Status Effect until the Generator stops regressing or a Survivor is damaged by any means.
The Aura of the damaged Generator is revealed to all Survivors in yellow.
Trail of Torment has a cool-down of 80/70/60

After picking up a Survivor, all Generators not currently being repaired by Survivors are blocked by The Entity for the next 16 seconds.

The Auras of blocked Generators are highlighted to you in white.
Thrilling Tremors has a cool-down of 100/80/60 seconds.

Each time a generator is completed, Coup de Grace grows in power.  Gain a token.

Consume one token to increase the distance of your next lunge attack by 80percent

You become obsessed with one Survivor.  When the Obsession loses a health state, your Terror Radius transfers to the Obsession for 30 seconds, and its radius is set to 32 meters.

You are granted the Undetectable status effect for the duration.

The Survivor with the transferred Terror Radius is also considered to be "inside the Terror Radius" for other purposes.

The Killer can only be obsessed with one Survivor at a time.  Undetectable hides the Killers aura, Terror Radius, and Red Stain.