[3.16] Immortal Infernal Minions Build (Skitterbots/Bestial Ursa/Spectral Spirits/Vorana's March)

Pros:
-Carefree playstyle with no main attack skill button, good for RSI!
-Zero minion micromanagement apart from the occasional Deathmark.
-Can spend all your time just dodging and running away from enemies.
-Skitterbots have massive range and speed and offscreen enemies often!
-Minions never die!
-Fast clear up to mid red maps.
-Pretty decent bossing up to mid red maps.
-Can do most content.

Cons:
-DPS falloff against endgame bosses
-This version could afford to build some more defense, slightly squishy
-Lower overall DPS than traditional spectres build

Several immortal minions exist in the game that are horribly underutilized:

Summon Skitterbots from the gem:


Spectral Spirits from Essence of Insanity will constantly be summoned from a weapon that is equipped such as:


Summon Bestial Minion from Yriel's Fostering:


Summon Arbalist from Vorana's March:


The problem is, all of these minions have terrible base DPS. In the case of skitterbots, they literally don't do any damage.
To our rescue comes Infernal Legion!


We scale the high base damage from this support gem as high as it will go, and proc damage increases from other means such as:

Exposure from Elemental Army:


Resistance Reduction from Combustion:


Debuffs from Predator and Feeding Frenzy:


Raze and Pillage from cluster jewel:


Amanamu's Gaze and Ghastly jewels with "minion damage if you've used a minion skill recently":

Necromancer. We take Mindless Aggression to path to Unnatural Strength which gives +2 to minion gems and that's essential to scale the Infernal Legion gem. Bone Barrier gives us nice defense since we always have minions up, and Commander of Darkness gives us more condition-free damage.

On the tree, we grab Life, Damage Taken Recouped as Life, Minion Damage, and Mana Reservation Efficiency. We can ignore minion attack speed or life nodes, as the degen only scales with minion damage. We also needed just a bit of mana and reduced skill costs as the reservation of a skitterbot skill with tons of links was costly.

For a cluster jewel, grab a minion damage jewel with Raze and Pillage, 2 jewel sockets for putting Ghastly jewels in, and 12 total passives. You can also throw in a Bodyguards notable if you want some knockback defense.


For my other jewels, I used Amanamu's Gaze and Ghastly Abyssal Jewels. To proc ignite and exposure, you'll need "Minions deal # to # additional fire damage". The damage scaling from "Minions deal #% increased damage if you've used a minion skill recently" is important and procced by binding Bone Armour to mouse move, and some taunt/blind chance is nice for defense:


Replica Fragile Bloom for regen was nice and had reservation efficiency:


Same deal with both a Fortress Covenant with reservation efficiency and Conqueror's Efficiency:


POB tree:
https://pastebin.com/etNXeUWb

Helmet (PARTIALLY REQUIRED):
Since we're scaling the Infernal Legion gem, you'll want mods like "+3 to level of Socketed Minion Gems", Socketed Gems are Supported by Level # Burning Damage/Minion Damage, Essence of Horror "Socketed Gems Deal #% More Elemental Damage". My helmet here has several mods that aren't even usable by skitterbots and it's kind of a waste- minion life and crit literally don't do anything and are wasted. Alternatively, Forbidden Shako can spawn with the rare mod "Socketed Gems are supported by Level 35 Infernal Legion" which would be BIS but good luck finding that. This is the most expensive part of the build, about 5-8ex cost:


Amulet (PARTIALLY REQUIRED):
You'll want mana reservation efficiency, and to craft minion speed to increase how quickly our burning minions can get to targets. Then just life and resistances and anoint with Ravenous Horde. Make sure to enhance quality with Fertile Catalysts to increase the roll of the mana reservation efficiency mod.


Body Armour (REQUIRED):
We want the immortal Bestial Ursa from that particular version of Yriel's fostering, as it still uses the old version of Rallying cry that generically increases ally damage, as well as taunts nearby enemies and does an AOE ground slam to help apply debuffs. To get 6 off-colours, do the 3B craft followed by 4-5-6 socket crafts until you get 6 blue, which shouldn't take more than about 6 or so tries and jewellers are dirt cheap this league at 3000 per exalted. No need to 6-link!


Rings:
We're tight on gem sockets like any minion build, so we need unset rings with life and resistances:


Gloves:
We want life, resistances, and an open prefix so we can craft "Minions deal #% Increased Damage". A good enchant would be "Of Light" or "Of Reflection" to either help proc Holy Relic and give us consecrated ground for survivability or to give us an additional minion that helps DPS:


Belt:
Again, since we're tight on gem sockets I chose a belt with "Grants Level # Enduring Cry" to help us survive better and get some endurance charges and healing. You could swap this out if you wanted for a Darkness Enthroned and more minion damage or some Stygian belt, but I chose to go a bit more defensive here:


Boots (REQUIRED):
Vorana's March gives us 3 more immortal minions to help DPS and apply debuffs to scale the damage! Ideally you'd have two pairs, one for clearing with "+1 number of summoned Arbalists", "Summoned Arbalists Fire +4 projectiles" and "Summoned Arbalists' Projectiles Chain +2 times", as well as one with the same additional arbalist mod and "Summoned Arbalists gain #% of physical damage as extra fire damage" and "Summoned Arbalists have #% chance to freeze, shock, and ignite/cause bleeding/poison" for more DOT scaled damage against single target. However, the single target ones are hard to find so here's what I use:


Main Weapon (REQUIRED):
I crafted this myself from a 1ex base synthesized bow with % minion damage implicit using Essence of Insanity followed by annulling until it was the only mod left, then multimodding with blocked suffix and "Cannot Roll Attack Mods" to be able to force slam "+1 to level of socketed gems", and then removed crafted mods and multimodded again with minion damage and attack speed with one last yolo slam (that sadly didn't go well). Use the same socket color trick as with the chest:


Main Offhand:
Slapped on some defense for life and block:


Main Swap Weapon:
Crafted the same style of Spectral Spirit weapon but on a sword base so I could use a shield, that way I could use shield charge and Berserk and Fortify in a pinch.


Main Swap Offhand:
Same theme as with the main quiver. Went for life, life gained on block, life recovered on block:


Flasks:
Yeah yeah, I know divine flasks are better but I just love the look of eternal flasks. Get seething divine anti-bleed and anti-freeze life flasks. Get a quicksilver flask with increased effect, movespeed, and enkindle it with more effect. I use Rumi's Concoction for the defense and Witchfire Brew for the DOT damage increase curse aura as well as the smokescreen:

Helmet:


Body Armour:


Gloves:


Rings:


Main Weapon (Bow):


Swap Weapon (Sword):


Swap Offhand (Shield):

This was some random map with a fight against Redeemer I remembered to record:
https://www.youtube.com/watch?v=NQBxTCk4A44