Bug : Tempest Flurry [Monk, Quarterstaff] , Mana Consuption

TL:DR - Tempest Flurry is using Mana Per Mob rather than Per Skill use. Update tooltip or apply a fix to the skill.

Tempest Flurry, when used on a group of enemies consumes mana per mob hit rather than per skill usage.

You can spam Tempest Flurry on a Rare or Mini-Boss and never drain mana to zero as fast as you can using Tempest Flurry on a small - medium or - large group of mobs.

I can go from 100% to 0% mana in a group of 5-6 enemies using Tempest Flurry. In the same amount of actions used / time in combat with a Rare or Mini-Boss no where near the same mana is used.

No where in the tool tip does the skill suggest 17 Mana per Mob hit per action. At most a full rotation of the skill is 17x4 (68 mana).

Tempest Flurry abnormal mana consumption confirmed , it cost at least twice as much what tag says, plz fix it