Fly up into the air with momentary invulnerability then plummet back down to the ground, staggering and dealing 100% heartrune damage within a 3m radius. Press the Heartrune Ability or Basic Attack input while hovering to trigger the fall immediately.
Item Cunning Heartrune of Dark Ascent can be crafted on Stonecutting Table tier III. You need 1 of Major Heartrune of Dark Ascent, 10 of Wooden Coin, 10 of Gypsum Orb, 1000 of Feathers, 50 of Vial of Suspended Azoth, 10 of Sulfur. In results you get 1 of Cunning Heartrune of Dark Ascent with 625 gearscore. For crafting required Stonecutting skill with level 0 or higher.