For all this time Phase Rush has been a crappy keystone, why does it exist as it is

Back when it was Stormraiders Surge it wasn't even that great/popular of a mastery, but it did what it was meant to and had it's uses on Assassins and Squishy low mobility mages

Why the hell hasn't the method of proccing it gone back to 1/3rd HP damage in a short amount of time? The 3 spell proc method makes no sense because you use all your abilities to followup with....nothing?

Bring back SS ples Rit