Quote Originally Posted by Avalon_Albrook View Post
Dreadwash is technically stunnable. Dreadstorm is not. If Dreadstorm starts to be cast, the hysteria puddle will not be stopped unless you manage to burn down the add before the cast finishes.
Pushbacks/Holmgang(pull-forward?) interrupt the Dreadstorm cast. So Fluid Aura, Garuda pushback and Holmgang can actually stop it from going off.
It is a very short window after it starts casting but it definitely works.