The core of the build is +70% condition duration and +80% might duration which lets you stack both might and vulnerability on the target up to around 20 stacks consistently. A long standing sigil bug (shared CD between swap sigils and on-crit sigils) prevents it from getting to 25 stacks in either.
Some terms I'm using in this guide that you may not be familiar with:
As usual with many necromancer builds, the major trait picks are very flexible. There are a few required picks though, and so I'll explain what they are, and what options are available.
20 Death Magic
You want to wear as much berserker gear as you feel comfortable in, and soldiers or split picks of knights/valks to make up the difference. Necros are in the relatively unique boat that their HP and Armor are well balanced (HP ~= 10*Armor), and this build doesn't put out much healing. I'm currently sitting at 45mil effective HP, which is the minimum level for meleeing a dungeon. Less than 45 million is considered more or less glass cannon, while more is increasingly durable. We're going to toe the line with this build, and count on dodges, well timed heals, party support, etc. to stay up. If you feel less comfortable playing squishy, don't hesitate to wear more soldiers gear to bring yourself to a comfortable level. Remember, dead = 0 DPS.
As for runes, take 2 sup. strength, 2 sup. hoelbrak, 2 sup. fire, for a total of +75 power and +60% might duration. This provides the bulk of your might duration, and without it, the build kinda falls apart.
For sigils, you want a sigil of battle on each weaponset. The other sigil has some options. Ideally, we want the sigil of strength on your other weapon, so we can get up additional stacks of might. Or we'd like the sigil of fragility to get additional stacks of vulnerability up on the target and help out our party. But both are on-crit sigils, and due to a longstanding bug, on-crit sigils share a CD with on-swap sigils. So the 9-10s CD on the sigil of battle permanently locks you out of any on-crit sigil, or any other on-swap sigil. The sigil of battle provides 9 stacks of extremely consistent might, and so dropping it is inadvisable. So that leaves us with less desirable options. First, we have the sigil of force which increases our damage by 5%. Second, we have the sigil of bloodlust which gets us 250 additional power. From a pure theory stand point, the sigil of bloodlust is better. However, because stacks are lost upon entering an instance, and upon going down, it's difficult to keep 25 stacks of bloodlust up at all times. Since the sigil of force gets you most of the way there (for me, the sigil of bloodlust is a 6.8% boost to EP, while the sigil of force is exactly 5%), and requires no upkeep, I'm currently favoring it. The sigil of bloodlust is the better option though if you can keep the stacks up.
As for food, there's no option but to take Rare Veggie Pizzas. It gives you +40% condition duration, which takes your total condition duration bonus to +70%, allowing you to maintain 20 stacks of vulnerability even while weaponswapping constantly. For this build to work, you have to ensure the food buff is on you at all times. Otherwise you'll lose most of your vuln stacks every time you swap weapons, and be starting from scratch. This makes you less effective, both in terms of damage output, and party support.
Your sets are axe/focus + dagger/warhorn. I'm playing with the idea of a variant that drops the warhorn in favor of just 3 weapons (axe/focus + dagger) so you're always on focus when you swap. This of course sacrifices an interrupt and some aoe damage, and it'll take some testing before I'll have any recommendations on the matter. But for now, here's how you play the weaponsets you have available with this build.
First, Blood is Power. It's the necro's best friend. I can't imagine a PvE build that doesn't run it. And we're built to make it as awesome as humanly possible. 10 stacks of might for 21s on a 24s CD, it doesn't get much better than that.
The other two slots are very open and you can pick your favorites. You can help your AOE situation by running epidemic to help the party out by spreading vulnerability around. You can run wells. You can run signets. It's really up to you. My favorites? I run wells when I'm in a party that doesn't coordinate fields. I've always loved wells, and love dishing out that aoe damage. And they do massive damage with this build. But some groups are well coordinated and very good at this game, and so they'll have noticed that dark fields are pretty much always superceded by some other field. For example, a scepter/dagger support ele is gonna be dropping blast finishers on a fire field for party-wide might to clean up trash extra quick and burst bosses when it's important. In this case, a poorly timed well can *ruin* the entire party's effectiveness. And besides, who's a dick to their dungeon group and *doesn't* bring signet of undeath? So what I do now is generally run the signet of undeath, and swap my utilities for every fight. Sometimes I just want a little more power, other times I want to clean up trash. I'll come back to this section later and fill in more details on how to pick situational utilities.
This build is focused on single target take down, i.e. boss fights. The idea is to flash death shroud and swap weapons every 10 seconds, on the nose. Death shroud gets you ~6 seconds of fury, and swapping weapons adds 3 stacks of might for nearly 30s. The result is a 60% fury uptime, and 9 stacks of pretty much constant might after 30 seconds into a fight. This means you're not at peak performance in short fights, and you have a 30 second warm-up period. It's a definite downside to this build. But you can get most of the way there instantly, and so you're not worthless in short fights. You're more like 75% effective after a well placed cast of Reaper's Touch (RT) / Blood is Power (BiP). Maintaining peak effectiveness takes practice to get the hang of. This is *not* an easy build to master. You need to get into the habit of popping death shroud and weapon swapping every 10 seconds, on the nose. While keeping up your damaging attacks (dagger 1 / axe 2), building vulnerability while on axe/focus, and keeping BiP on CD at all times. And you need to keep yourself alive.
Against trash you want to walk in with dagger equipped. Flash death shroud, pop focus 4, BiP, swap to axe, and hit 3 early in the fight. This will give you 13 stacks of might, put vulnerability on as much of the trash as possible, and pass retaliation out when it's most important. Then pick the strongest target, auto attack to build vulnerability on him (and use epidemic if you're running it), and start weapon swapping when it's off CD.
Against bosses, it's less important which weaponset you open with, since the fight is much longer. Get your might up, start stacking vulnerability, and start swapping weapons as appropriate. The idea is to phase in and out as appropriate for the fight and the weaponset you're on. While on axe, build vulnerability with axe 1 / focus 4 (keep focus 4 on CD against single targets), and burst as often as possible with axe 2. When the 10s are up, flash DS/swap weapons, and dart in there really put some numbers up with dagger 1. Use the other 4 weapon skills to keep yourself alive. It's more important than doing damage, I promise. And when the 10s are up, swap back and retreat to 600 range. In some fights, melee range is just too dangerous. Hell, sometimes axe range is too dangerous. Keep a staff handy in your inventory just in case. Again, dead = 0 dps. Play smart, maximize vulnerability, maximize might, maximize damage dealt, minimize damage taken.
Be the wraith -- deadly, but untouchable.
I'll add more as I see fit, and as I tweak the build.
Thanks for reading!