I am calling for a curious investigation into Shadowblight to identify new synergy points to make it a real endgame build.
The buff to reapers pursuit made it good, but it requires Ebonpiercer to scale the skill ranks and provide additional DOT procs.
The Season 7 content helped as well, enabling witch powers to apply base damage as a DOT did help proc Shadowblight and the new Gem did enable dots to tick faster.
However, it needs some new juice.
Since Shadowblight builds require a dump into either Shadow DOT stats (to bump the Shadowblight multiplier) OR crit damage, we are bound by the limited options we have.
Idea 1:
Change the damage type.
Shadowblight could benefit from the Wither paragon node.
From a fantasy perspective, I find it hard for a direct damage proc which is derived from a DOT which “withers” the enemy to not also progress the enemy’s withering.
The enemy is affected by Shadowblight, which is, in a gaming sense, a debuff. But from a fantasy sense they are really afflicted by Shadowblight. An affliction which continuously deals shadow damage, could be argued as actually being a DOT effect even if its invocation mechanism is DOT ticks from other effects instead of being invoked by a skill cast.
How do we implement this?
From a technical perspective, Shadowblight itself could be classified as Shadow Damage Over Time. Simply with a variant tick which is determined as it is today, the number of DOT ticks against the target.
But if Shadowblight itself is classified as Shadow Damage Over Time wouldn’t it also count against Shadow Damage Over Time against the target which would increase the number of times the Shadowblight damage procs? Precisely, Yes! Because… The Withering effect should be unanimously agreed upon to be progressive or exponential. The more a body or flesh is subject to effects that wither it away, the more withering effects should have on it.
Floating damage text won’t be a problem, just group it like it’s grouped for DOTs, let shadowblight’s total procs and total damage aggregate every 0.25 seconds, then apply the total damage and number of shadow damage over time procs to the enemy.
To tune the ramp time. Scale the number of DOT ticks required to proc Shadowblight damage. Boom!
Idea 2:
Just wrap that effect into a unique RING to test it out labeled “The Abyss”. Text could read:
“Shadowblight’s damage is now applied as Shadow Damage Over Time and when Shadowblight damage is applied to an enemy, it strikes the enemy an addition 5-10 times.”
The second effect could be added because I’ve been patient 
Final thoughts:
With this, we all win. the Shadow DOT build starts slow, and ramps up leaving nothing but dry dust where life once stood.
Imagine the special effects you could dream up for a ring called “The Abyss” which has the sole purpose of accelerating the decay of what ever it touches.
Let’s create some real Darkness with “The Abyss”.