Biggest issue I see here is the lack of synergies between the two power sets. Obviously, this is more of a thematic build, and AoPM is a reasonable choice for most hybrid power set builds, but Quarry would support both these power sets better and probably give better survivability and definitely more DPS.
AoPM makes for a very easy time playing and supporting, and this build would work just fine with it, but it has been demonstrated that the offensive passives still give more DPS (and some even more survivability).
I would find a way to take the heal advantage for Summon Shadows, as you're depending on Lifedrain as your main heal, which will limit your overall DPS. Same issue with Holdout Shot and Stimpack. Ego Sprites with the heal advantage is another good choice for a Darkness-themed character.
I don't have much experience with Ebon Rift and Planar Fracture, and I realize they are mostly thematic choices, but you probably could do better DPS-wise (Ego Sprites/Void Horror?). You have a better AoE power already in Lead Tempest, and more time spent not using it will hinder your DPS.
Comments
AoPM makes for a very easy time playing and supporting, and this build would work just fine with it, but it has been demonstrated that the offensive passives still give more DPS (and some even more survivability).
I would find a way to take the heal advantage for Summon Shadows, as you're depending on Lifedrain as your main heal, which will limit your overall DPS. Same issue with Holdout Shot and Stimpack. Ego Sprites with the heal advantage is another good choice for a Darkness-themed character.
I don't have much experience with Ebon Rift and Planar Fracture, and I realize they are mostly thematic choices, but you probably could do better DPS-wise (Ego Sprites/Void Horror?). You have a better AoE power already in Lead Tempest, and more time spent not using it will hinder your DPS.