Welcome to "Power in Death"... UPGRADE! This is an end-game tanking build for the necromancer class. It is an improved version compared to the non-upgraded one, but is also more involved to get together. This build has about all the flexibility that you'll need in terms of skills (which you should always discusss with your trial lead and the other tank). The sets on display are what I run in most situations, but again discuss what you need to bring with the trial lead and the other tank :)

Now as for the build. It utilizes some great passives of the necromancer skill lines combined with some of the more recent sets to make maximum use of arguably the strongest ult in the game 'Frozen Colossus'. But that is not all. Because we combine the amazing debuff provided by this ult, together with the incredibly strong warhorn group buff (major force), all in one.
This build has incredibly fast ult-regen (a frozen colossus every 30-40 seconds or so if you get some corpses, which you make yourself) and some of the highest damage mitigation in the game thanks to your skills and passives.

Swap-outs (sets):
must-have sets to have around (apart from the ones listed in the gear section) in case you are tanking a trial:
- Powerful Assault (jewellery, one-handed weapon, shield, ice staff)
- Claw of Yolnahkriin (jewellery, one-handed weapon, shield, ice staf, body pieces)
- Lady Thorn (monster set)
- Bloodspawn (monster set, easy beginner set)
- Magma Incarnate (monster set, only for dungeons)
- Tremorscale (monster set, only for stam-dd heavy groups)

Swap-outs (skills):
You have two skills which you can use as swap-out: Overflowing Altar (main swap-out) and Agony Totem (rather not but can do).
If you are wearing Powerful Assault swap Overflowing Altar for Echoing Vigor.
The other skills which are unclocked are very situational and dependent on group composition and personal preference. If you have the time and are willing to put in the effort, try to get these abilities but the ones slotted are the main ones you are looking to get.