Each boss has a Forsaken Power that is unlocked after hanging their respective bosses trophy on their Forsaken altar. All Forsaken powers share the same 20-minute cooldown, which does not reset or reduce even when the player logs off or changes their active Forsaken power. By default, the Forsaken power is activated by pressing F.
The player will not be able to activate a Forsaken Power until defeating a boss and hanging its trophy.
When activating a Forsaken Power, allied players in a small radius will also receive the benefit of the Forsaken Power activated. Thus, a party of four players can keep a Forsaken Power activated virtually indefinitely by consecutively using each player's Forsaken Power.