You become obsessed with one Survivor.
Each time you hit a Survivor other than your Obsession with a Basic Attack, Save the Best for Last gains 1 Token, up to a maximum of 8 Tokens:

Gain a stack-able 5 percent Cool-down reduction on successful attacks per Token, up to a maximum of 40 percent.
Each time you hit your Obsession with a Basic Attack, Save the Best for Last loses 4/3/2 Tokens.

When the Obsession is sacrificed or killed, you can neither gain nor lose any more Tokens.
You can only be obsessed with one Survivor at a time.

Your base Terror Radius is increased by 8 meters.

Whenever you are outside of a Chase, your Terror Radius is reduced by 16 metres while your Field of View is increased by 3/5/10 °.
Field of View gains do not stack.

Destroy dropped pallets, breakable walls, and generators 20percent faster.

After damaging a generator this perk becomes active for 60 seconds.

The generator regresses at 200percent of the normal regression speed and you can se its aura in yellow.

Each time a Survivor completes a good Skill Check on a generator affected by this perk, you receive a loud noise notification.

At the start of the Trial, 4 random Hooks are changed into Scourge Hooks:

The Auras of Scourge Hooks are revealed to you in white.
Each time a Survivor is unhooked from a Scourge Hook, the following effects apply:

The Auras of all other Survivors are revealed for 5/6/7 seconds.

Any Survivor who blinds you or stuns you using a Pallet becomes the Obsession.
Anytime your Obsession switches to another Survivor by any means, that Survivor then suffers from the Oblivious Status Effect for 40/50/60 seconds and their Aura is revealed to you for 4 seconds.
You can only be obsessed with one Survivor at a time.