After cleansing a Totem, Overzealous activates:

Increases your Repair speed by 6/7/8 percent if it was a Dull Totem.
Increases your Repair speed by 12/14/16 percent if it was a Hex Totem.
Overzealous deactivates when losing a Health State by any means.

Your ferocious tenacity in dire situations allow you to benefit from the following effects:

Increases your Crawling speed by 30/40/50 percent.
Grants the ability to crawl and recover at the same time.
Reduces the volume of Grunts of Pain while in the Dying State by -75 percent.

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.

Once the Exit Gates are powered, No One Left Behind activates:

Increases your Unhooking and Healing speed by 30/40/50 percent.
Grants 50/75/100 percent bonus Bloodpoints for actions in the Altruism Category.
Grants the unhooked Survivor a 7 percent Haste Status Effect for 10 seconds.
The Auras of all other Survivors are revealed to you.