The Black Cloud rune for the Wailing Arrows skill either has a typo or a bug. It says "Reduces the Cooldown of the Skill" in the description of the skill. When I select the rune, the cooldown, however, increases instead of decreasing. Please see the images in this link: https://imgur.com/a/Q3bYU2m. Why I say this could be a bug is that is it meant to say "Reduces the Duration of the Skill" since the skill duration is reduced as a result of equipping this skill.