Latest patches built a great foundation for Vitality Decay damage to stop being a meme. It is a potent playstyle nowadays. That said after playing quite a few decaying specs I have noticed that there could be more support for it. Here are my suggestions:
1) Add Vitality Decay to more relics
Currently Oathkeeper has the best Decay relic in form of Meditation while Occultist and Necromancer don’t really have much to write home about. I think that those two relics can benefit from adding Vitality Decay damage rolls: Dreeg’s Affliction and Impurity. Dreeg’s Affliction could also benefit from having equal Vitality/Acid damage rolls.
Crazy idea: add Vitality/Vitality Decay as third damage to Shaman’s Eye of the Storm or Massacre (can also add Decay to its proc). Shaman is a prime Vitality mastery yet none of its relics support that.
2) More Vitality Decay in devotions
Currently Vitality Decay builds are using non-native devotion with conversion from gear to stack dots. I think some Decay could be added to devotion procs of Wendigo or even Bat. Dying God or Abomination could have a duration bonus somewhere. I also think that Affliction not having any direct damage bonuses is a bit weird. It’s an expensive devotion, why should it hamstring Acid/Vitality players by not having any direct damage bonuses?
Maybe someone can suggest more places where Vitality Decay support could be better.