This looked like something i would like let me know about your opinion. This build is assuming that later levels and difficulties will have enemies that have resistances to specific damage types.
Gargantuan Alabaster - If the stun works with attacks too would provide alot of CC during big fights. Plus Gargantuan is a nice pile of meat to absorb some damage.
Locust Swarm Alabaster - AoE damage, poison oriented, and the cloud left over will add as a nice DoT
Mass Confusion Crimson - Help stur things up, giving me time, space, and increased damage not only from the demons attacking each other but another 80% to sync with other spells
Big Bad Voodoo Crimson - This will sync perfectly with mass confusion and gargantuan; allowing more stuns, improving damage output of confused demons, and hopefully stacks with Mass Confusion Crimson rune stone
Haunt Golden - More AoE; DoT; Arcane damage another source; Golden increased mana regen
Firebats Golden - Close damage to burn anyone down who gets to close for comfort; Fire Damage so another source; Golden for life steal
Pierce of Veil - Increase my damage, hopefully this will sync with mass confusion and Voodoo for an insane overall multiplier of my damage output
Rush of Essance - Increase mana regen for Haunt hopefully the return will be able to keep me afloat
Blood Ritual - Split my heavy mana costs from Pierce of Veil; Health Regen; allows me to cast more and longer since i am not fully mana based anymore and have leech from a couple different sources
DoT = Damage over time
CC = Crowd Control
AoE = Area of Effect