And before I forget, what I like about Heavensward DRK; Blood Price being usable outside of Grit and making spamming Dark Arts+Abyssal Drain actually fun until Blood Price fell off, Dark Arts+Dark Dance had synergy with Dark Arts+Dark Passenger in dungeons and some bosses before everything started to become immuned to blind status, which could be be paired with Bloodbath cross class skill and Blood Weapon, Low Blow could be spammed with enough parry and with Dark Dance base effect, and alternating between combo paths.
As clunky as Stormblood DRK was with Dark Arts spam became with the nerfing of Blood Price and removal of some actually good skills, Reprisal no longer requireing a parry proc was a blessing although it should have stayed 15 second duration and still had it's damage potency, along with Low Blow/Leg Sweep(because they're basically the same skill with the exact same animation) keeping it's damage potency, although it did make certain Role Actions pointless unless certain fights had forced tank swaps making DRK not really viable until after making all role actions be available were DRK was able to get some footing unless knockbacks/draw ins were a thing in which case DRK was shelved yet again until they decided that some fights should just punish knockback prevention but at the point it was too late, but the idea of extending Blood Weapon/Blood Price is a good concept and The Blackest Night is/was pretty good even though it did justify Quietus and Bloodspiller for late game but Quietus did get buffed to have some interaction with MP which made up for the nerf of Blood Price and the 4.3 buffs were just so good but some of the effects could have been better.
And now to build off of Heavensward and Stormblood DRK;
- Dark Dance should come back with it Dark Arts effect base line
- Dark Passenger/Plunge/Abyssal Drain should have the Dark Arts effect base line
-Carve and Spit needs to deal 3 hits with 200 potency in a row, each hit restoring MP or Dark Arts potency is baseline
-Darkside needs to last 30 seconds and have the Bloodbath effect built-in with Power Slash combo extending duration to max. 30 seconds
-Dark Arts can either be 90 second recast that increases the potency of all GCD actions by 50% and and lower all GCD recasts to 1.5 seconds(if Blood Weapon/Price is active 2 seconds otherwise) for 20 seconds or works the same as it did in both Heavensward and Stormblood but only affecting GCDs
-Blood Weapon becomes Blood Price but with some changes to make it not overpowered(i.e. no MP refresh when you get hit but still passively generates blackblood since your melee/auto attacks are still generating blackblood on hit and maybe cut MP costs in half)
-Delirium going back to being a weaponskill that extends Blood Weapon/Price duration to max. 30 seconds, applies Scourge damage over time and/or a healing over time for 15 seconds
-Syphon Strike has the Souleater effect but also applies a heal shield and remove blackblood generation from Souleater but it now applies a heal shield that last 15 seconds(to help strech out defensive CDs)
-Sole Survivor recovery effect applies to all party members
And now look at the "new" stuff that Shadowbringers has and how to apply it to this brand new DRK;
-Stalwart Soul remain mostly unchanged.
-Flood of Darkness/Shadow need to be GCD and costs less blackblood but extends both Darkside and Blood Weapon/Price timer
-Edge of Darkness/Shadow is GCD but is used to spend excess blackblood
-Living Shadow is an upgraded Living Dead but no longer has those annoying pre-requisites and fully heals the DRK and make them impervious to most damage for 10 seconds(basically a better Hallowed Ground)
And finally, give DRK traits that make Reprisal and Low Blow useful...