Survivors repairing or healing within your Terror Radius suffer from the following effects:

Increases the Trigger odds of Skill Check by 10 percent.
Decreases the Success zone of Skill Checks by 40/50/60 percent.

For each Survivor you hook for the first time, No Way Out gains 1 Token.
Once the Exit Gates have been powered, No Way Out activates:

When a Survivor interacts with an Exit Gate Switch, you receive a Loud Noise Notification and The Entity blocks both Exit Gate Switches for 12 seconds and an additional 6/9/12 seconds per Token in your possession, up to a combined maximum of 36/48/60 seconds.

After a generator is repaired, The Entity blocked the generator with the most progress for 30 seconds.  You see its white aura during this time.

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.