What was the direction intended for Phase Rush?
I can't see how it will see use from any classes in it's current state. Before it was used on mages (ryze/vlad)/melee assassins to escape after bursting someone or chase down people with immobile juggernauts/bruisers like Illaoi/Garen.
Right now, you can't do either on most champions, it's harder to proc, has a 50% longer cooldown and for some reason starts at a useless 15% movespeed that scales with level, returning to Stormraiders Surge speed at level 18. On top of that, it doesn't even provide slow resistance for the mages that may use it.
There's a lot of sub-par runes/keystones at the moment but this really takes the cake...