Azure, on 13 July 2015 - 01:57 AM, said:
Any thoughts on this build would be appreciated, especially on the choice of condi vs power, sigil choice, and necromancer vs nightmare runes. Thanks for reading

I was hoping someone else would respond to this. I used to run a tanky condi necro quite a bit, but now I mostly run power/DPS. I enjoy the more active power/DPS play style... so I guess that sort of answers your first question.
For sigils on a condi build.... You have four typical choices: (1) increase the intensity of your conditions (Sigil of Corruption, Sigil of Bursting, Sigil of Geomancy); (2) increase the duration of your conditions (Sigil of Malice); (3) increase the diversity of your conditions (Sigil of Torment), or (4) increase your defense (Sigil of Energy). Sigil of Doom fits in two of the above categories.
I don't have a lot of firm advice on which of those sigils to choose. However, in my experience, you will get more out of a Sigil of Torment than you will with a Sigil of Malice. This is more about having an extra "cover condition" than the actual torment damage. You are almost always going to end up with lots of bleeds on your target. The more conditions you stack on top of those bleeds, the harder those bleeds will be to clear. Sigil of Torment will give you an extra condition to cover your bleeds without using Tainted Shackles, which has a long CD. The extra cover condition will probably net you a longer effective condition duration given all the condi-clears out there.
Personally, I run geomancy/energy on my staff and torment/corruption on my scepter-dagger. With Mark of Evasion as a minor in the blood tree, you can dodge (applying bleeds from the mark) right before swapping to staff (applying bleeds from Geomancy, and getting the endurance back). This keeps your condi pressure high, as you move from your more offensive scepter/dagger set to your more utility-oriented staff. The idea is to get your opponent more focused on clearing conditions than actually fighting you, especially as you go on the defensive.
Regarding runes on a condi build... I run perplexity. While confusion does nice damage on a condition build, it is (again) more about covering my bleeds than actually dealing confusion damage.
This is slightly less viable now that Path of Corruption is competing with Terror. However, you can still interrupt with Doom, Reaper's Mark, and Corrupt Boons (on stability). Plus, you get the occasional random confusion procs from getting hit.
The other reason I run perplexity runes is that they make the condition necro a little more fun to play, as it adds another tactical wrinkle to the build.
I'd post a specific build, but I don't really have one that's been flushed out and thoroughly tested using the post-patch traits... and its not a really high priority for me. I did spend a couple of nights stomping bads on a curses, blood, soul reaping build... but bads are bads, so no trick there.
Good luck.