I rrally hope this set isn't for real when the patch goes live. Even though I don't like this set, I also agree (yes I am one of those Stam meta players) that most of if not all of the stamina based weapon ults are completely OP especially the morph of the 2H that restores the ult cost if it kills someone (#newWB).

This would probably be the most overpowered pvp set of all times if this goes online
Don't even think, you can nerf to a point where it is not overpowered.

A few things should be noted;

This does not work on Boss mobs. Bosses have since been made immune to blind and miss chances ever since a few players got a hold of the old level 45 version and used it in c160 content.

It is a single target proc, meaning it can only blind one enemy at a time. This means it only really gains value in 1v1 situations in terms of PvP.

It has a guaranteed 5 second ICD, which gives a brief period where there is clear counter play to the set.

Sets that have both proc chances and ICD's often suffer from horrendous RNG and comes out much weaker than the math may suggest.