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.

When you unhook a Survivor, the rescued Survivor benefits from the following effects for 4/6/8 seconds:

Scratch Marks and Pools of Blood are suppressed.
Additional 7 percent Haste Status Effect, boosting their Movement speed.
Guardian reveals the Killers Aura to you for 8 seconds.

After being unhooked or unhooking yourself, Off the Record activates for the next 60/70/80 seconds:

Prevents your Aura from being revealed to the Killer, if they attempt to read it.
Suppresses Grunts of Pain when injured.
Grants the Endurance Status Effect.
This effect is cancelled prematurely if you perform a Conspicuous Action.
Off the Record deactivates once the Exit Gates are powered.

You can see the Scratch Marks of other Survivors.
Whenever another Survivor loses a Health State within 32 metres of you, the Killers Aura is revealed to you for 3/4/5 seconds.

After being healed from or having recovered from the Dying State, Soul Guard grants you the Endurance Status Effect for the next 4/6/8 seconds.

Any damage taken that would put you into the Dying State will instead trigger the Deep Wound Status Effect, after which you have 20 seconds to Mend yourself.
Taking any damage while under the effect of Deep Wound or if its timer runs out will put you into the Dying State.
Soul Guard allows you to completely recover from the Dying State when you are affected by the Cursed Status Effect.
Soul Guard has a cool-down of 30 seconds.

When within 6 metres of a hooked Survivor, press the Active Ability button to halt their Sacrifice Process for the next 20/25/30 seconds.
If the hooked Survivor has already entered the Struggle Phase, its Skill Checks are paused for that duration.
Reassurance can only be used once per Survivor per Hook Instance.