From Guild Wars 2 Wiki
Hint: Use the Gloominator to capture the darkness at a portal to Grenth's domain in the battle for the Cathedral of Silence in Cursed Shore.
— In-game description
- Using the Gloominator while under the effect of Grenth's Domain.
- To obtain the effect, you need to stand in the whirpools that spawn on the north and south sides of the room during the attack on the Temple of Grenth.
- Since the game update of June 28, 2016, one portal/whirlpool is also present while the Temple of Grenth is under the Pact's control. The portal is on the left as you run inside the temple.