ALL MY BUILDS FOCUS ON USING UNDEAD WARFRAMES WITH WEAPONS FITTING THEIR THEMES. THEY MAY NOT BE THE ABSOLUTE BEST OPTION FOR IT, BUT I STILL MAKE SURE THEY'RE MORE THAN VIABLE ENOUGH.

INTRODUCTION

The main focus of this build is to make use of [Nekros Prime]'s full arsenal, being able to collect as much loot as possible while also buffing our shadows for high level content. To do so we follow these steps:

1. Cast Desecrate and keep it active, then switch to operator and do chained slings for +40% ability strength before casting Nourish for energy regeneration and viral damage.
2. Kill a few enemies fast, using Terrify if you need to get rid of armour or shield gate.
3. Cast Shadows of the Dead when you killed enough enemies (preferably 7, but can be less if under heavy fire) to get stagger, knockdown, and status immunity along with more damage reduction the more enemies you kill (capped at 90% after 188 enemies). If you're early in the mission you can do chained slings before casting, getting 88.5% damage reduction from the get-go.
4. Re-cast Nourish to provide viral damage and bursts to your shadows, buffing them and making them able to kill enemies.
5. Keep killing enemies to add stacks of Molt Augmented, re-casting Shadows of the Dead + Nourish whenever needed, and casting Terrify whenever you need armour strip or de-aggroing.

BUILD SPECIFICS

FOCUS SCHOOL

We use either Madurai for this build. The nodes we care most about are:

• Phoenix Talons: This gives us a little bit more damage, but more importantly it also gives out shadows extra damage.
• Power Transfer: This gives us +50% cast speed when we switch in and out of our operator. This is perfect for casting Shadows of the Dead.
• Void Strike: This gives us +1000% damage to our amp and weapons for 8 seconds, making things trivial if you're fast enough. Sadly it has a 40 second cooldown. It's best to use when you've just started the mission and don't have any galvanized or arcane stacks up.
• Void Fuel: This gives us a 40% chance to not consume ammo while Void Strike is active, while helps quite a bit for sustained damage.
• Sling Strength: This gives us +40% ability strength for 20 seconds after consecutive chained void slings. Perfect for buffing Shadows of the Dead for 88.5% damage reduction at the start until we get enough stacks of Molt Augmented.

ARCHON SHARDS

• Crimson Archon Shard:
  +15% Ability Strength x2. This is to get to 100% armour strip from the get go. While we can slowly build up ability strength with Molt Augmented to get 90% damage reduction with Shadows of the Dead and not rely on Sling Strength, we don't wanna compromise at all on Terrify.
  +15% Ability Duration x1. That'd make Nourish and Terrify last for just over 40 seconds, while making the health bars from Shadows of the Dead drain slower.
• Amber Archon Shard:
  +37.5% Casting Speed x2. Both Terrify and Shadows of the Dead benefit greatly from this, so the more casting speed you can get, the better. We don't need more than two since we already get +50% cast speed from Power Transfer.

STATS:

• STRENGTH: We use [Blind Rage], Molt Augmented, and two archon shards. With this we'll get to 169% ability strength from the get-go. It'll take 188 kills to get to the 214% cap for [Shield Of Shadows]' damage reduction. Molt Augmented will eventually bring the damage multiplier of shadows from 253.5% to 343.5% at full stacks. Until you get enough stacks you should switch to operator and do chained slings to get +40% ability strength. With that it'd only take 17 kills to get 90% damage reduction.
  Nourish also benefits from this, going from 2.01x energy multiplier and +76% viral damage to all weapons to a 2.37x energy multiplier and +102% viral damage at full stacks. And even more if you add chained slings to it.
  The amount of enemies affected by Terrify per cast are also affected by ability strength, starting with 33 and ending with 45 at full stacks.
• DURATION: We use [Primed Continuity] and an archon shard. All our abilities besides Desecrate benefit from duration. At 170% ability duration both Nourish and Terrify would last 42.5 seconds, while Shadows of the Dead would have a 1.76% health drain.
• RANGE: We use [Overextended]. All of our abilities benefit from ability range.
  Nourish's starting buff cast is affected, but it also affects the viral bursts that come out whenever you or your shadows are shot, increasing their radius.
  Terrify affects a large amount of enemies with our current ability strength, but it'd mean nothing if it doesn't have a big AoE. At 190% ability range you'll be just under the 30 meter mark, but we sadly can't add more range mods.
  Desecrate lives and dies by its range, so increasing it is always optimall. 47.5 meters seems to be enough for most ocassions.
  Shadows of the Dead doesn't benefit directly from range, but the links from [Shield Of Shadows] do. At 190% ability range the links have a radius of 95 meters, making it so you don't have to recast Shadows of the Dead to bring them close to you as often.
• EFFICIENCY/ENERGY: We use [Preparation], [Primed Flow], and [Equilibrium]. With how much energy we get because of Nourish a bigger energy pool tends to be better than less energy per cast, which is why we chose [Primed Flow] over [Streamline] or [Fleeting Expertise]. Desecrate is up at all times, and it ends up creating a massive amount of energy and health orbs. Because of that we make the most out of it by putting [Equilibrium] on our [Nekros Prime], effectively filling up our energy at all times. There's also a lot of ways to get energy regeneration, be it the focus shool Zenurik or the mods [Energy Siphon], [Energy Nexus], and [Xata Invocation]. The last one is what we use in this build, but if you don't have it you can use any of the other alternatives if you want energy regeneration.
  As for [Preparation]... why use it when you can generate energy with energy orbs, health orbs, regeneration, and get even more thanks to nourish? Well while it's true you won't need it when you got your run going, I've always found the hardest part of starting a high level run as [Nekros Prime] to be the very start when you can't cast lots of abilities. This gets rid of that issue, giving you more than enough energy to cast and use Desecrate, cast Nourish, and use Terrify a few times comfortably before casting Shadows of the Dead and getting your build going.
  The calculation for starting energy is:
  Base Starting Energy + (5 x (Mod Capacity Left + Extra Aura Capacity)) + (Total Energy x [Preparation] Multiplier).
  [Nekros Prime] starts with 75 energy. Our aura gives us 14 extra capacity, and our [Preparation] gives us a 73% multiplier and leaves us with one capacity left. That'd make our calculation be:
  75 + (5 x (1 + 14)) + (541 x 73%) = 544.93. which is max energy.

LOADOUT:

• PRIMARY: We use the Kuva Bramma. This is a great damage dealer in general. Since we have Nourish active at all times we can keep it as mostly pure Toxin damage to deal with corpus units, while [Hunter Munitions] gets rid of grineer and if you don't feel like waiting you can always armour strip them with Terrify.
  I chose this weapon thematically because you literally get it from a Lich, and it's one of the few Lich-exclusive weapons.
• SECONDARY: We use the Grimoire. This is a great support weapon. While [Nekros Prime]' Terrify can definitely help you kill enemies with it, the most important thing about it is [Xata Invocation] giving you up to 10 energy per second, which benefits from Nourish. If you don't have this you might have to consider using the Zenurik focus school instead as an alternative for energy regeneration, but you miss out on a bunch of other benefits from Madurai.
  I chose this weapon thematically because a necromancer is a dark magic caster that revives people as undead, so of course they'd have their own grimoire or necronomicon.
• MELEE: We use the Hate. This is perfect for group 1-shotting with its heavy attack, dealing incredibly strong bleed procs. It now has an incarnon mode which, along with the tennokai, make this weapon fully viable for a light attack build.
  I chose this weapon thematically because a reaper should use a scythe.
• COMPANION: We use the Panzer Vulvaphyla. A necromancer should have an immortal pet, shouldn't they? Besides spreading even more viral this companion makes sure you have even more crit damage and fire rate, while also providing health gating in the off chance you receive fatal damage. You could also use a Smeeta Kavat for the chance at double drops if you wish, but you lose on the fire rate and melee combo buffs along with the extra viral stacks and health gate, so I don't think it's worth it.

GAMEPLAY ELEMENTS:

• SHIELD GATING: We use [Brief Respite]. At 116 energy per cast Terrify gives us +174 energy each time, filling up a big chunk of our shields. That coupled with our 99% damage reduction from [Adaptation] and [Shield Of Shadows] it makes use able to health tank comfortably up to a certain level. If we're planning to do level cap runs then damage reduction becomes worthless we you can replace [Adaptation] with [Catalyzing Shields], giving us full 1.3 seconds of shield gate invulnerability with every cast of Terrify. We could replace both arcanes as well, preferably for ones that help us kill things faster.
• AUGMENTS: We use [Shield Of Shadows] and [Creeping Terrify]. [Shield Of Shadows] provides survivability by giving 90% damage reduction and drawing fire away from you, while also giving stagger, knockdown, and status immunity, saving us from having to use [Primed Sure Footed] and [Rolling Guard] respectively.
  [Creeping Terrify] gives us 80% slow on all affected enemies, which is basically a mini Gloom-like effect. This effectively gets rid of Terrify's main drawback of having enemies run away from you.
  We don't run [Despoil] because of how incredibly easy it is to keep your energy filled up now thanks to Nourish.
• SURVIVABILITY: We use [Shield Of Shadows], [Adaptation], and Arcane Blessing. As stated above, Shield of Shadows will prevent stagger and knockdown effects, while also preventing you from suddenly dying of toxic procs from eximus units. [Adaptation] boosts this up further to the point that in most steel path content you'd never ever go down. Even if you managed to get hit enough that your shields go down you'll still have over 1500 health thanks to Arcane Blessing, which is more than enough to tank while you cast Terrify and kill everything around you. As mentioned above as well both [Adaptation] and Arcane Blessing can be replaced for Catalyzing Shields and another arcane when doing level cap content.

BONUS BUILD - 0 FORMA OPTION

So, if you want to test this build but are too worried that you won't like it and will waste forma on it, here's a 0 forma version of the build for you to test. 0 Forma builds always MAKE compromises, but I try to make them as close to the original to give an accurrate representation when testing.

MOD CHANGES:

• Preparation removed: We just cannot, in any way, shape, or form, add this mod with the amount of polarities we have.
• [Primed Continuity] to [Continuity]: Due to the lack of an aura polarity among other things we're pretty tight when it comes to mod capacity, so we'll have to downgrade it. Thankfully it isn't that much of a loss.
• [Primed Flow] to [Flow]: We don't have enough mod capacity at all, so we'll have to work with less max energy than usual.

And that's it! Besides downgrading two mods and removing the exilus all the mods are exactly the same, just in different spots since we can't change polarity positions with 0 forma. While it's a bit harder to start the run due to the lack of [Preparation] and smaller energy pool, it should still be more or less the same.