I think the WoWhead article did a good job of assessing Havoc’s flaws. Seeing as I don’t touch that spec with a 10ft pole, I’m in no position to give credible advice on how to improve it. That being said…
I think what the article highlights more than anything, is how precarious of a position Havoc is in. Without borrowed power, it’s functionally a potato. With borrowed power, it’s broken.
What that tells me is that the spec is just a skeleton (moreso than some other classes), and it needs meat (first to make it not reliant on borrowed power, second to dilute the power of individual abilities). Make First Blood talent baseline as recommended.
Add 3-4 meaningful abilities - I can’t imagine what those would look like because class design isn’t my job. A quick look at old DH NPCs gives some ideas, however.
- Leotheras could summon “inner demons,” shadowy enemies that would target players. This, I feel, is a solid idea if it is given some utility.
- Netharel had an ability called “Debilitating Strike” that reduced the physical damage that enemies dealt. Seeing as Blade Dance’s Dodge is being deleted (and Havoc’s overall DPS is being nerfed), there’s no harm in giving Havoc some mitigation.
- Almost every TBC Demon Hunter had abilities that specifically targeted spellcasters. Abilities that would make spells less effective, as well as Mana Burn. I don’t see this meshing well with anything the spec has, however.
All of these ideas have their issues of course, and I’m not saying these are what needs to happen. However, if we’re going to make the class not a potato after its nerf, looking at the traditional DH NPCs is a good place to start. The biggest concern is not stepping on the toes of warlocks any more than we already have (seeing as Ion is allergic to the idea of two classes having Metamorphosis).
Also, take a look back at borrowed power in Legion and BfA. What worked, what didn’t, what was overpowered. Take the good ideas, make them NOT ridiculously overpowered, and add them as baseline.
Other than that… I don’t know. I have plenty of bad ideas on what direction to take classes and specs. This is likely why I will never be (and should never be) hired to do class design.