(edited by Cyte.5840)
sigil/runes of torment question
The bigger question is what are you trying to do with the torment? If its to stop enemies from moving, the small amount of damage it does is not going to help. If its for aoe damage torment could be your best bet, just remember sigil of blight also exists, but its real purpose is to mess with healing. You could even swap out the sigil of earth for blight so you have even more aoe damage.
Torment for necros is better used for condition protection. That is to make it harder for an enemy to cleanse conditions off themselves. At that point your trying to load them up with them so they cant cleanse the right ones off.
The bleeds from sigil of earth will end up doing more damage to a single target then sigil of torment, but are easier to counter. Id try it and go with runes of the the krait, with them you have the same amount of condition damage, less torment and when ever you use your elite you spread out bleed, poison and torment.
Just remember you only need sigil of corruption on one of your weapon sets, any kills when that weapon of will add to your stacks.
For a different option if your running corrupt boon, runes of antitoxin will trigger off of it. Meaning each time you use it you gain 5 stacks of might for free