For Necromancer, there are lots of build options:-
1) Elemental Array Spammer:- http://www.rpg-gamin...33d42a54c61e701
2) Defensive Controller:- http://www.rpg-gamin...33d42a54c61e701
3) Pyrelectnecromancer:- http://www.rpg-gamin...31142a54c61e701
4) Pyro-Electro Bomber:- http://www.rpg-gamin...31142a54c61e701
Important note:- If you are a Human and have 32 ability points, pick Rejuvenating Barrier passive in the Spirit tree or Swift Aegis upgrade for Aegis of the Rift focus ability or Wildfire upgrade for Immolate.
I will address each build specifically before moving onto the general Necromancer tips:-
I) Elemental Array Spammer
This build is a close quarters combat build whereby the Necromancer gets right up close to the enemy, spams Chilling Array and Flaming Array followed by Walking Bomb and what have you. It is a high risk, high reward build since with the right combination of enchantments and apparels, it will give you the highest damage out of any mage specialization. At the same time, with a few toggles, you can turn this build into a crowd controller defensive build for ranged spellcasting alongside crowd control and survivability. This build is excellent for solos.
II) Defensive Controller
This build is a ranged build that gives a Necromancer incredible survivability on top of crowd control. For defense, the Necromancer has Barrier, Simulacrum passive, Death Siphon and Chilling Array. For crowd control, the Necromancer has Horror + Terror, Lightning Cage and Chilling Array. For damage, the Necromancer has Searing Glyph, Energy Barrage, Walking Bomb and Lightning Cage. The only difference between Elemental Array Spammer and Defensive Controller is that Defensive Controller is a ranged build. I would personally recommend this build for Dorian, provided you remove Lightning Bolt and Gathering Storm and replace with Static Charge to save ability points. Or you can have your Inquisitor equip defensive potions and play a support role with some damage. This build is viable for solos.
III) Pyrelectnecromancer
This is a ranged build that sacrifices Chilling Array and Ice Armor for Chain Lightning. It provides a great deal of flexibility at the cost of survivability because with this build, you can deal with any type of enemy effectively on top of having decent crowd control in the form of Horror + Terror and Lightning Cage. If you encounter annoying Qunari that are immune or highly resistant to fire and frost, you can switch to a pure Lightning build and wreck them. If you encounter enemy that are weak to fire, you can switch to a pure Fire build and wreck them.
IV) Elemental Bomber
This build replaces Horror and Immolate with Wall of Fire. Wall of Fire is a 2-in-1 spell whereby it has fire damage and it panics / fears enemies, which goes really well with Blinding Terror passive. Otherwise, it is identical with Pyrelectnecromancer build. Horror + Terror is great for definitely locking down and killing one or two clustered enemies (if Horror + Terror is not resisted, drop a Searing Glyph or Flaming Array and the enemy is as good as dead) whereas Wall of Fire is great for lots of enemies as well as its low mana cost and damage over time which synergizes well with Static Cage. The only thing is that this is not much of a Necromancer, more of a Walking Bomber + Fire + Lightning.
Armor, Enchantments, Weapons
i) The best armor enchantments are the ones that help with spell cost reduction and increase chance of critical hits for Flaspoint passive and because Necromancer spells are quite costly.
ii) The best masterwork enchantment I would recommend for a Necromancer is Fade Touched Snoufleur skin that provides heal on hit because it synergizes really well with Death Siphon as well as Simulacrum to heal you.
iii) As for armor and apparel set, the best one for a Necromancer is the one you find in Trespasser :- Skin That Stalks, Bind That Guides, Eye That Weeps, Hand That Cuts, Ring of Doubt together with Encore staff. However, be warned that the armor Skin That Stalks look awful on anything other than Elves or Human Females.
Roleplaying
Why Necromancer ?
A. Nevarran death mages are the best schooled and best educated Circle Mages outside of the Tevinter Imperium mages. They are most definitely more educated and better trained than members of the The Mages' Collective and Chantry-approved mages. Learning from the best is a good thing.
B. Viuus Anaxas is ironically the sanest, most lucid and best teacher amongst the mage specialization trainer. By talking to him you realize that the man know his craft, respects his craft, and he explains very well what Necromancy entails - Use spirits to terrify (Horror), give the dead purpose once more (Spirit Mark), and rend the battlefield (Walking Bomb). By contrast, the other mage specialization trainers, quite frankly, a not very good. Commander Helaine spender her time pulling rank, yapping about being on the front lines of battle and focusing solely on Spectral Blade instead of a thorough teaching of the Knight Enchanter discipline. Your Trainer is Fade-Addled and spends her time rambling about how the Inquisitor should be a Rift Mage because they are the Inquisitor and because its primordial power. Put simply, neither of them seem to be good teachers whereas Viuus Anaxas is.
C. Being a Necromancer makes you Inquisitor scary. Part of being a Necromancer involves terrifying people to death. That can be a good thing if you want people to fear you (even a little bit), especially if you are an anorexic Elf.
D. Being a Necromancer is practical. As Inquisitor and the Herald, you will spend your time killing a lot. Why not make use of all that death, it seems wasteful not to do so.
E. The Inquisitor is interested in learning more about spirits and death as well as being drawn to the taboo. None of the Inquisitors, be it Circle Mage or Dalish First or Tal Vashoth Saarebas are taught more about spirits and death because it is a subject that is taboo in many Circle of Magi, amongst most Dalish and the Qunari. Knowing something that many mages and non-mages do not can be give one the upper hand.
General Tips
a. Necromancers can fire off two Walking Bombs in quick succession for the cost of a single Walking Bomb. The same is true of Energy Barrage which can proc masterworks and Flashpoint passive.
b. If you play as a Necromancer with Chilling Array + Ice Armor, consider using Fade Touched Imperial Vestment Cotton (Walking Bomb on hit) because you can detonate that masterwork Walking Bomb in addition with the Walking Bomb you cast.
c. Necromancer's advantage include high burst damage, especially when paired with Ring of Doubt, Flashpoint, Clean Burn, Gathering Storm and Power of the Dead. Necromancers also do not have to worry about lightning staves or lightning abilities because there is no Shock-Weakness bug that affects Necromancers. Heal on hit and heal on kill enchantments go very well with Simulacrum and Death Siphon to create a Necromancer that is practically immortal.
d. Necromancer's weakness is mana regeneration, spell cost and long cooldowns. This is why we use Fade Step + Energizing step as well as Gathering Storm and spell cost reduction enchanments.
So there you go - Detailed tips for all three mage specializations. Hope you have fun and cheers.