Wind Shear

Wind Shear is an instant cast spell that interrupts any channeling spell from the target, and it also prevents the target from casting for 2 seconds any spell that uses the same School of magic as the interrupted spell. Unlike other shocks, it reduces your threat instead of causing damage. Though its cooldown is the same as the other shock spells, it is not shared with the other shocks.

It is trained at level 16 for. Like similar abilities, the amount of threat reduced by the spell will increase as you level up.