Each time a Survivor other than yourself is killed or sacrificed, Sole Survivor gains 1 Token, up to a maximum of 3 Tokens:

Each Token grants a stack-able radius of 20/22/24 metres within which the Killer is unable to read your Aura, up to a maximum of 60/66/72 metres.
Once you are the last Survivor standing, you benefit from the following effects:

Increases your Repair speed of Generators by +75 percent.
Increases your Opening speed of the Exit Gates and the Hatch by +50 percent.
Increases the odds of becoming the Killers initial Obsession by +100 percent.

The Killer can only be obsessed with Survivor at a time.

Increases the Efficiency of your Items by 15/20/25 percent.
Streetwise extends its effect to all other Survivors within 8 metres of your location and lingers for 15 seconds.

The Auras of Generators are revealed to you within 32 metres.
Each time a Generator is completed, Visionary is deactivated for 20/18/16 seconds.

Press and hold the Active Ability button for 6/5/4 seconds while standing beside a dropped Pallet to reset it to its upright position.

Grants the ability to see the Auras of all dropped but not yet destroyed Pallets in the environment.

After repairing Generators for a total of 33 percent, Wiretap activates:

After repairing a Generator for 3 seconds, press the Active Ability button to install a Wiretap, which stays active for 60/70/80 seconds.
The Auras of trapped Generators are revealed to all Survivors in yellow.
When the Killer comes within 14 metres of a trapped Generator, their Aura is revealed to all Survivors.
Damaging the Generator destroys the Wiretap.

Unlocks potential in your Aura-reading ability.
The Auras of Breakable Walls, Pallets, and Windows are revealed to you within 24/28/32 metres.