Here are my ideas in a simple way, that makes the general gameplay smoother in my humble opinion.
->Removed Dark Mind
->Changed the functionality of Living Shadow and Abyssal Drain.
->Added Scourge
Enhanced Oblation - Trait
-> Increases Oblation's damage reduction to 15%, duration to 12 seconds and grants a heal over time of 200 potency. ( 200 * 4 = 800 potency heal total )
Reason: Oblation is an augment to TBN, meaning you generally use it at the same time as you use TBN to get more value. If you used it and TBN doesn't break, than using just Oblation is better. TBN acts as DRK's strong, personal mitigation, however before Oblation got introduced, you had Dark Mind which acted like an Oblation but only to magic. So at this point to mitigate something which is ( best case scenario ) magic damage you got to use TBN + Oblation + Dark Mind, which barely puts you on the same level as a PLD using Sentinel + Holly Sheltron, despite pushing 3 buttons. On the OGCD heavy job...
Abyssal Drain - Ability
->Deals damage with a potency of 150 to target and all enemies nearby it.
->Gradually restores HP depending on the number of enemies hit, across 15 seconds. Each enemy hit grants a heal over time potency of 200.
Reason: Using Abyssal Drain every 60 seconds is too rare, so either making it available more often, or changing its effect to a regen.
Scourge - Ability
->Delivers an attack with a potency of 150.
Additional Effect: Damage over time
Potency: 60
Duration: 18s
Combo action: Syphon Strike
Reason: Now you have to do something while not having Delirium up.
Living Shadow - Ability, Lasts 24 seconds
Merge with Fray to become one with your inner darkness.
-> Increases the potencies of all attacks by 250 potency.
-> At level 88, the potency is increased to 300 via Enhanced Living Shadow.
-> Darkside passive is increased from 10% -> 20% more damage, while under the effect of Living Shadow - given by the trait Enhanced Living Shadow II.
Reason: With this change players should feel more in control and feel like they are the ones actually doing the damage.