Vial of Purified Water

Acquisition
This is a temporary skill that can only be obtained and used during the Nundu Bay mission. It is used to defeat the Harbingers of Twilight and the Harbinger of Nightfall. The skill is obtained from Elder Jonah at the beginning of the mission, and remains in your skill bar until the mission is over if you choose to equip it instead one of your other skills.

Trivia
The Vial of Purified Water may be inspired by the common myth that "holy" water may be used as an apotrope against evil supernatural creatures like demons or vampires.