[2.3] Spectre/Curse/Aura Necromancer with MoM/EB/ZO. Beginner friendly

Mistress of Sacrifice - Your Offerings also effect you
Flesh Binder - 1% physical damage reduction for each zombie you have, for you and your zombies.
Soul Reaver - 100% increased damage and life for specters.

Mistress of Sacrifice is pretty ridiculous. Flesh Offering now gives much needed clear speed, while Bone Offering gives amazing defenses, if you're ever in a position where you might need them. Don't hesitate to have both gems available at all times and swap when needed!
Flesh Binder is a solid 8-10+ % decrease in physical damage taken, which is just awesome.
Soul Reaver = basically immortal spectres that do double damage.....what?

Commander of Darkness is now amazing. So good that we're now running a lvl 1 clarity, just to cheat in another 10% damage for our minions and some castspeed for ourselves. The main reason the build went from 3 to 2 curses, so we can have more auras.

Stats you want on gear: Life, ES, Resists, +Dex +Str or +All Attributes helps too. A Strength Belt with Strength, Life and resist rolls is pretty nice to have. Dex Amulet also helps.


Helm with +2 to minion gems

Raise Zombies, Fortify, Minion Life, Stone Golem, switch later to Animate Guardian with Leer Cast and Dying Breath.
You can also use Zahndethus' Cassock for chaos resists and Concecrated Ground on Block.

Your Guardian has 35% resists on all difficulties. Gets 16% from nodes. More from minion resist jewels. Even more from Purity of Fire and Commander of Darkness. So you don't even need resists on Boots or Gloves, or at least not much. Rest of the budget goes into Maximum Life, Energy Shield, Armor, Life Reg. DON'T GIVE HIM MOVEMENTSPEED! It makes him survive longer. So no quality Animate Guardian gem either. Unless you're absolutely sure he wont die by getting in the mobs' faces faster.
Guardian isn't worth it without Leer Cast and Dying Breath. Make sure his resists are capped and he has +life on gear. He will be you best buddy, if you take good care of him.

If you're really worried about the Guardian dying and loosing his gear, put him in the shield and weapon swap if he's about to die. Mine has yet to come even close to dying up to tier 10 maps.


6L Chest (Tabula Rasa early on):

Raise Spectre, Spell Echo, Minion Damage, Greater Multiple Projectiles (Lesser Multiple Proj is also an option. Slightly more damage, worse AoE), Fire Penetration, Elemental Focus

Vis Mortis is BiS for endgame. Otherwise a good 6L Chest with high ES, Life.

Instead of using Multiple Projectiles you can also use Elemental Destruction. Sacrifice AoE for even more damage. You can also use both and just swap before entering a Boss Room as long as you're using Tabula Rasa. Bosses have not lived for more than 10 seconds so far with using GMP. On higher level maps you may need the extra dps though. Try out both and decide what's best for you.


4L Boots of Ullr:

Curse on Hit, Ball Lightning (lvl 1), Enfeeble, Temporal Chains

4L Gloves:
Faster Casting, Flame Dash (lvl 1), Desecration, Convocation

Weapon: 3L Auromvorax:

Increased Duration, Vaal Haste(lvl 8 is easy enough, more if you have the dex for it), Flesh/Bone Offering


Victario's Charity:

Discipline, Grace, Purity of Elements


Rings:

Unsocket Rings for Summon Stone Golem and a lvl 1 Clarity


Amulet

Citrine Amulet with good life, es, resist rolls. Try to get a lot of your dex on this piece.


Jewels:

Minion Damage, Increased Life/Minion Life, + to all stats or anything useful really.



Flasks:

1. Seething Divine Flask of Staunching (instant flask, remove bleed)
2. Sapping Eternal Flask of Animation (BIG heal over 4 seconds, also heals your minions)
3. Saturated Divine Flask of Grounding (LONG over time heal, shock removal on the flask you spam the most)
4. Experimenter's Granite Flask of Warding (curse removal and immunity on a 6 second duration flask)
5. Chemist's Quicksilver Flask of Heat (Triple Use movement speed flask, removes freeze)

People have different preferences, when it comes to flask. Use your own judgement as well.
Combinations can be different. You absolutely want to remove bleed, heal minions and remove curses though.


Swap Weapon Slot:

Desecrate (if you're not using an unset ring), plus whatever gems you want to level.

Good gems to quality are: Raise Zombie (+life, really good), Minion Life (+life), Minion Damage (+dmg), Greater Multiple Projectiles(+attck/cast speed), Spell Echo (+dmg), Elemental Focus (+dmg), Fire Penetration (+fire dmg), Offering Skill (+duration), Increased Duration (+duration), Fortify (+duration).
Raise Spectre and Animate Guardian get movement speed per quality, which isn't that useful. Aura Skills, and Vaal Haste get +radius, which can be useful. You can of course level all gems to 20, use vendor recipe (lvl 20 gem + gemcutter's prism = lvl 1 gem with 20 quality) and just level the gems again. Takes a while to do though. Very cost efficient on the other hand.


Mana Reserved is 98% since we take -22% mana reserved on the tree.

Leveling as a Summoner is unfortunately way too painful. So I'd suggest leveling with Flame Totem and Firestorm.
Leveling Build
Get a Quartz Scepter (20% elemtental damage) with the right sockets from a vendor. Use the following recipe: Magic Weapon + Orb of Alteration + Resistance Ring(Fire Res ring for + 1 to fire skills)
Put Flame Totem, Fire Penetration and Faster Casting in it.
Get a second Quartz Scepter with +1 to fire skills, or just any offhand. Put Firestorm and whatever you have (Spell Echo, Faster Casting, Elemental Focus, Added xyz damage) in it.
You can switch over to a summoner build at around level 60. You need access to cruel flame sentinels and at least 11 respec points

Switch to Summoner Build
Take out points spend on totem skills, put them into ES nodes at witch start, take out the 2 int nodes north of the witch start and connect through the mid instead.
Next points should go into more minion nodes, curse nodes, keystones, aura nodes

1. Go to Cruel Solaris Temple or Merciless Eternal Lab (Merciless Eternal Lab is lvl 68 = better spectres)
(2. Swap to second weapon slot and use desecrate 3 times)
3. Hold A for corpse targeting and raise some Flame Sentinels
4. Repeat Steps 2 and 3 until you have all your spectres
5. Swap back and summon zombies, use more swaps and desecrate if needed
6. Summon Golem, Animate your Guardian put on Auras
7. Run around, spam ball lightning with right click and drink coffee, while loot falls from the sky.
8. Use Flesh/Bone Offering whenever it runs out. Use Vaal Haste against Bosses for ultimate tryhard mode

Note: If you cannot get Flame Sentinels to spawn, remake the Instance.