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.

While carrying a Survivor, increase your Carrying Movement speed by 6/12/18percent.  Increases your Terror Radius by 12 meters.

Survivors within your Terror Radius have a 50percent penalty to healing progression speed, and healing Skill Checks move 50percent faster.

The Auras of Survivors, who are healing or being healed, are revealed to you when they are within a range of 20/24/28 meters.