Tank [Nekros] [Shield Of Shadows] build for endurance Steel Path. This has good range, a fully functional energy pool, and high ability strength. The general gameplay is to be careful at the start when you still lack the kills for [Shield Of Shadows], [Health Conversion], and Arcane Blessing stacks. Once you have it up and running you might as well be undying. Terrify is both a panic button for crowd control and a 100% Armor Strip on everything that isn't a boss. Nourish provides Viral Damage which is the best damage to have with armor strip and it will solve any energy deficiency if you actively use it because its similar to Arcane Energize. It also buff your Shadows with it too but don't expect to become too lazy with them because the aiming from Shadows is almost as bad as the clones from Star Wars. Desecrate is the trademark ability of [Nekros]; use it well so you don't ever need to farm rare drops again. It also drops tons of Health orbs, ammo, etc. Desecrate farming is more effective with Slash weapons like Feralx, Pyrana Prime, Reaper Prime, or the Amalgam Ripkas True Steel for their gore effect.

• For Aura, anything that suits your fancy goes; I would suggest either [Brief Respite] or [Growing Power]. I think that Combat Discipline is good too, and it can be used to produce viral stacks and to trigger Arcane Avenger. Also, the self-damage is reduced by armor and shields of shadows damage reduction into a measly 1. Nekros passive is that he gains 5 health on kill within 10 m, so this self-damage can be negated entirely through this passive and through the numerous amounts of health orbs from desecrate.

• [Power Drift] for 15% Strength. Primed Sure Footed isn't needed since Shield of Shadows provides CC immunity, including knockdown, stagger, etc.

• [Overextended] to obtain a reasonable range on both Terrify and Desecrate. 190% Range is the sweet spot; any less and it's somewhat awkward to Desecrate and any more Terrify becomes counterproductive unless you slot in Creeping Terrify somehow.

• [Blind Rage] for the large bonus to strength to offset [Overextended]. The negative efficiency is being completely offset by Nourish, Flow, and Equilibrium. Corrupted mods drop from Deimos Orokin Vaults, you need to open those with a Decaying dragon key.

• [Primed Flow], [Archon Flow], or [Flow] you need to use one to obtain a larger energy pool since the base energy pool of Nekros is small. I got mine from trading but it should arrive from Baro every now and then.

• [Equilibrium] has been core to [Nekros] build as far as I can remember due to his Desecrate. It will heal all your missing health and restore any missing energy. To get more loot from Desecrate, it is better to slice the enemies into smaller pieces with Slash weapons. Farmable from Lephantis boss on Deimos.

• [Primed Continuity] or [Continuity] is needed so that Nourish isn't annoying to refresh. Also, it offset Shadows of the Dead decay rate which is nice for keeping them alive for longer. All primed mods arrive with Baro.

• [Health Conversion] will provide a substantial amount of Armor for tanking on Steel Path with its 83.1% Damage reduction. You will always have a surplus of health orbs so long as you don't forget to Desecrate. You can buy it from the yellow Cephalon that asks you to scan certain enemies for him.

• [Adaptation] is the bread and butter of any health tank build. If you lack it then, you need it ASAP or you'll suffer on Steel Path. It drops from from Arbitrations. It is less reliable than Health Conversion but they stack together into more or less ~98.31% Damage Reduction.

• [Shield Of Shadows] is the core mod of this build. It makes [Nekros] into an undying tank as it provides 90% Damage reduction with enough strength and Shadows. It stacks with both [Adaptation] and [Health Conversion] into ~99.831% Damage Reduction. Also, you want to use a bright energy color such as orange for your teammates. I got mine from Red Veil, but there might be another syndicate with it.

• Arcane Blessing makes up for [Nekros] low health pool. It's more effective than any other mod or Arcane in raising your total effective hit points. You buy it from Zariman Yonta, she wants the Lua Thrax found in Lua Circulus.

• Molt Augmented is critical to achieve the 167% Ability Strength needed for the 100% Armor Strip from Terrify and the 214% Ability Strength for the 90% Damage Reduction with Shield of Shadows. You can buy it from Zariman Calvalero with holdfast standing.

• For Archon shards, I would really recommend using 2 Amber Casting Speed instead of a [Natural Talent]. If you want you could use a Tau Ability Strength shard to either begin the match with a 100% Armor Strip or to exchange [Power Drift] with a different mod. Then, you could use 1 Azure Armor Max to stave you off before you obtain those [Health Conversion] stacks, same with 1 more Azure Health Max to stave off Arcane Blessing. Eventually, you'll unlock Cavia once you complete the Whispers in the walls quest gaining the option to fuse archon shards. Once you reach rank 2 with Cavia, you can fuse shards into Violet Archon shards, Topaz shards, and Emeral shards.

• If you want to slot in Arcane Avenger then do so instead of Molt Augmented. It will have a reliable proc through [Combat Discipline]. To make this work replace [Equilibrium] with [Transient Fortitude] for a total of 209% strength. You will definitely need 1 ability strength shard to gain the 214% strength necessary for the 90% damage reduction from [Shield Of Shadows]. Also, 1 Azure Energy Effectiveness and 1 Azure Health Effectiveness to make up for the missing Equilibrium or two Violet Archon shards for their equilibrium-like effect. This works very well; I have played with it before.

Enjoy and have fun, Tenno!

Disclaimer: It will eventually [Reach] a limit, but its tanky enough for the vast majority of endurance runs. If you want to go further, then instead of [Health Conversion], equip [Catalyzing Shields] to shield gate with Nourish, Terrify, and Shadows. Also, you can also replace Adaptation with Rolling Guard for a more shield gate/[Rolling Guard] oriented [Nekros].