As the environment of the sura realm was fatally poisonous for his clan, Gandharva used this skill to purify an area. As it could not purify it perfectly, weaker members of the clan still suffered.
Although the duration of this skill is not limited, it continuously drains vigor at a fast rate. Therefore, it is hard to maintain if the vigor recovery rate cannot keep up with the consumption.
Gandharva has used this skill on multiple occasions. He used it to block Agni's white flame and to prevent Agni from chasing Maruna. He also used it in Kalibloom while he was in his sura form.