Halcyon's Ascent is a legendary amulet in Diablo III. It requires a minimum character level of 61 to drop. The amulet can prove to be useful for builds centered around the ultimate shapeshifting abilities (Witch Doctors, who cannot shapeshift, get the improved Big Bad Voodoo instead). The 'jump uncontrollably' effect is, in fact, a repeating knock up, frequency preventing the enemy from movement or attacking. In the endgame, it is not as effective due to most enemies being immune or highly resistant to Crowd Control.