After unhooking a survivor, all survivors who are at least 60/50/40 meters away from that hook have their Aura revealed to you for 4 seconds.

After hooking a Survivor, THWACK! activates:

The next time you break a Breakable Wall or a Pallet, all Survivors within 28/30/32 meters of your location will scream and reveal their Aura for 4 seconds.

Instead of snuffing Boon Totems you destroy them.
Destroying a Boon Totem this way reveals the Auras of all Survivors that were within its range at that moment for 6/7/8 seconds.

When you search a locker, the auras of all Survivors within 8 meters of any lockers are revealed to you for 5 seconds.

This perk has a 30-second cooldown.

Grants the Undetectable status effect after gaining Bloodlust Tier 1.  The status effect is removed once you lose Bloodlust.

Gain 50percent more Bloodpoints for actions in the Hunter Category.

Grants the Undetectable Status Effect after standing still for 4/3/2 seconds and until you are moving again.