[2.5] Occultist - Could use some build feedback

Greetings, I'm just coming back to the game after a long hiatus and could use some help refining my Occultist build. Here's what I've brainstormed so far:

Skills
Essence Drain - Void Manipulation - Controlled Destruction - Rapid Decay - ?
Contagion - Void Manipulation - Faster Casting - Increased AoE - ?
Vulnerability
Clarity
Discipline
Lightning Warp

PoE Planner
http://poeplanner.com/AAUAAPMTAAB334rpAkuuGyXZW20ZEVA1uacrHU-X9FJTPV-XlS2LH8creCycIvRsC5Mnf8YRlg5ItzDoWiaIBx6VLvDVSVGP-lxAh8unm3WezxXsGCy_FdeGrlZjXIp7176KytO0DOq6DXxd8isKES_rY7VIdoLIDEyz0B_v6zsNEQ-smPfXm6EYajlSWAdSr61KZ_yESFxrw22PRqcIna4abOQi1abtPJo7gpuf3-98PAXAZvfBTm2lxJwyoS9tbOd02xoQe7466NYi6sM6ieDmWJMfSRO00Ra_aoz1b8gUotmw2N-wfPCRB0J6enC7_BV-xveSdAAAAAAA

I'd like to go CI and eventually link blood magic support to one or two auras to activate pain attunement. Are there any must have unique items that I should try and get? Any improvements to my passive tree? Thanks!