I just noticed that you have no ACC slotted in Gloom. I can see that you want to use this power as a proc mule, but if the power can't hit the target - all those procs will never activate. Edit: Your using Gloom to only spawn spectrals. My mistake. Edited again: I would slot a 6th slot in Gloom so that this attack could be used as a traditional attack that procs a bunch. This way, your slotting for the actual attack and the Spectrals. I would slot a +5 ACC enhancement.
Dark Blast, Gloom, Life Drain
These powers now have a 70% chance to summon a Spectral Minion to your side!
These Specters are temporary, lasting a maximum of 90 seconds as their health fades away by the second.
These Specters cannot be healed or regenerate, but have decent resistance to all damage and defense against AoE attacks.
These Specters cannot be commanded or upgraded, but slotting your personal attacks will improve their attack stats.
Each attack can only summon one Specter, for a maximum of 3 if all attacks are used.
Additionally, I strongly suggest you slot ACC in Zombie Horde. Oh, my. Those guys spawn 2 levels below you!