Your summary is accurate. The H90 set as it existed on the PTR (either iteration) has problems. Here’s an abbreviated breakdown.
Strengths
- Shreds lone elites/RGs that don’t spawn adds
Weaknesses
- Bastion’s chains spread Stricken stacks and reduce single-target damage in density
- Damage reduction and CC vulnerability
- Lack of mobility
- 2-piece bonus is nullified by a Frenzy rune
- No distinct identity or purpose
This set and its build are fundamentally at odds with themselves. The set’s greatest strength–its ability to shred lone elites and RGs that don’t spawn adds–is undermined by density or spawned mobs. This is because the chains from Bastion’s do two things:
- They spread damage across multiple targets instead of keeping it focused on a single mob.
- They distribute Stricken stacks to mobs other than the one we’re attacking.
What’s more, the 2-piece bonus is a total mess. Both Fear and Frozen are hard CC effects. After a few hits of either, mobs will go CC immune. That’s already a problem, but it gets worse, because the real problem is that every Frenzy attack has a 30% chance to Stun due to having all runes granted by our Frenzy belt, Undisputed Champion.
Think about that for a second.
Frenzy attacks very fast–its attack speed increases with every stack after every attack. We want this since faster attacks mean more healing (from Simplicity’s Strength) and more Stricken stacks. It also means more damage per second (DPS).
But the faster we attack, the more Stuns we apply. The more Stuns we apply, the faster mobs go CC immune, and once they are CC immune, we no longer reap the benefit of the set’s 2-piece damage bonus (a x3 multiplier).
In short, the set and supporting items conflict and work to neutralize a crucial set bonus.
By playing the build correctly, we literally break a set bonus.
How the flip did that ever get off the drawing board?
Well, there is an easy–and I mean easy–fix: Change the 2-piece bonus to “enemies affected by your Shouts” and there you go. Fixed.
But even if that change occurs, we still have to deal with the fact that there are two known bugs with Bastion’s revered–one that nerfs our damage when we use COE, and one where the item drops with fewer affixes than it should.
Finally, the 6-piece bonus doesn’t do enough damage. It doesn’t need a huge buff, but it certainly needs a booster shot, or the build will be very good at absolutely nothing.