The player holds the Storm Ruler with both hands at shoulder level and points it toward their target, in a posture very similar to that of the Stance skill. Once five seconds have passed whilst in this stance, the blade will become imbued by furious winds. The player may then smash it onto the ground, unleashing with this an extremely powerful storm wave forward, capable of felling even a giant.
While still wielding the sword with both hands, press and hold the Left Strong Attack button ( / ) once more to acquire an offensive stance and then press either the Right Weak Attack button ( / ) or the Right Strong Attack button ( / ) to unleash a two-handed slam attack on the ground which will call in a powerful storm, sending it forward.
Almost a requirement for fighting Yhorm the Giant (although he can still be defeated by conventional means, though with much more effort).
Regardless of what the description states, it will only inflict regular damage to any other giants apart from Yhorm.