Here’s an alternative to the traditional Lost Souls skelemancer that leans hard into the skeleton philosophy of quantity over quality.
- [Pet] [1.2] Skelespam! - Skelemancer Cabalist (CargoPants)
- Damage: Pets
- Active Skills: Raise Skeletons, Reap Spirit, Summon Blight Fiend, Bone Harvest, Ill Omen, Curse of Frailty, Mark of Torment, Blood of Dreeg, Sovereign
- Active Skills: Master of Death, Bonds of Bysmiel, Mogdrogen’s Ardor, Necrolord’s Shroud, Presence of Might
The Mythical Guardian of Death’s gate is one hell of a weapon. It gives -3 second cooldown to raise skeletons, +3 summon limit, and serious pet stats. On top of that it gives flat resistance reduction that gets stapled to Bone Harvest due to the %weapon damage. The only downside is that it’s a two hander, making it incompatible with the Lost Souls set. A set that provides much needed survivability to the fragile skeletons. But what if that survivability isn’t needed?
With Undead Legion maxed out, Raise Skeletons has a 10 second cooldown. Guardian of Death’s Gate gives -3 seconds, and since we’re not bound to the Lost Souls set, we can use the Spectral Crown and Mythical Sovereign Ruby of Domination for another -5 seconds. That gives us raise skeletons on a 2 second cooldown. At 3 skeletons every 2 seconds, that’s 1.5 skeletons per second! Who needs durability with numbers like that?
Grimtools: Cabalist, Level 100 (GD 1.2.0.3) - Grim Dawn Build Calculator
With introductions out of the way, lets talk details.
Pet stats with/without temporary buffs. Note that actual %damage is about ~450% higher due to full vitality conversion and various vitality damage buffs. (Necrolord’s Shroud, Spiritbinder Glyph, etc)
Performance:
This build is able to do any and all content - with varying degrees of success.
Ravager: Not a terribly hard fight. Takes about 1:45 minutes
Mogdrogen: I killed Mogdrogen before I realized you could only do it once. 
Didn’t time it or take a screenshot or anything, and it definitely wasn’t with an optimized version of the build. Rest assured it is doable, but unfortunately the proof is left as an exercise for the reader.
Crate of Entertainment: Not too hard of a fight, just don’t get killed. Took about 45 seconds.
Callagadra: Skeletons is probably the worst possible strategy to bring against Calla. With all the AOE damage she spits out it’s pretty easy for her to kill 1.5 skeletons per second. In spite of that it is doable, mostly because of the unkillable Reap Spirit Wraiths and double Fiendflesh from boots/shoulders. Took about 7 minutes, and more skeletons than I can count.
Crucible: Takes about 7-8 minutes to run Crucible 150-170. The maps that are all open and flat are definitely harder but thanks to the taunt on Blight Burst, all maps are consistently doable pretty much regardless of mutators.
Shattered Realm: SR 90 takes about 6-7 minutes, mutators, maps, and bosses aren’t too much of a factor. The build is perfectly happy nemesis hunting in SR 90, but you have to be careful on maps with a lot of ground hazards. Between hazards, hoards of trash, and nemeses, my rule of thumb is that you can pretty reliably handle any two of those at a time. If you end up in a spot where you have to deal with all three at once it can get ugly. Particular bosses to be cautious of are Fabius, Moosilauke, and Kaisan. All three can and will kill you if you’re not careful.
SR 95 is definitely doable, though not consistently within the timer and mutators are much more of a factor. I suspect the build could make it to SR 100, but I haven’t taken it there so I don’t know for sure.
Gear:
Weapon - Mythical Guardian of Death’s Gates: As mentioned, this is the key piece the build is focused around. All other gear/skill decisions will be informed by this one.
Helmet - Spectral Crown: The additional -3 second recharge as well as the skill bonuses are both vital. Not really any other competition for this slot. Only question is what affixes do you want?
Amulet - The least important of the cooldown reducers. Even with focusing almost exclusively on pet offense, you can pretty reliably keep the ranks full with a 4 second recharge. That being said, for CR 170 and SR 90+ the 2 second recharge provides a lot of security. The granted ability Sovereign is also a nice DPS push against tough bosses. That being said if you don’t plan on doing deep SR/Crucible you could probably run just about any amulet you like.
Medal - Wendigo Gaze: Just the best medal for skeletons. Not much else to say
Rings - Mythical Spiritbinder Glyph (x2): The main thing here is getting full elemental → vitality conversion for the skelewizards. Getting Reap Spirit to 23/26 for the 3’rd wraith is also relevant. I did a lot of testing with Bloodsworn signets but they just didn’t perform as well.
Belt - Mythical Shadowfiend’s Cord: Another one that I didn’t really expect to be BiS, but it beat out the Lunal’Valoth belt and Mythical Spiritseeker Cord in terms of performance.
Armor - Mythical Necrolord’s Shroud: Important for the +3 to Undead Legion and Will of the Crypt.
Gloves - Mythical Bonescavenger’s Deathgrips: Mainly for the +4 to raise skeletons, but more spirits are fun 
Boots - Mythical Fiendflesh Boots: Great pet boots overall, and help get Blight Burst to 17/26 for the taunt.
Shoulders - Mythical Fiendflesh Mantle: It sucks that none of the skill bonuses really help us, but the pet stats and second instance of fiendflesh are too good to pass up. You can survive a lot with double fiendflesh.
Pants - Bysmiel-Sect Legguards with specifically chosen affixes: These provide the best pet stats you can get from pants, but if you don’t like affix hunting or using grimtools, then just whatever pet pants you have lying around will get the job done. This goes for pretty much all the affixes in this build. I was able to cruise through the main campaign, ravager, and SR 75 with passable self-found gear so the highly specific affixes are really just for those last few points of optimization.
Skills:
This build has quite a lot of skills - especially for a pet build. It’s definitely not lazy and you’ve got to keep an eye on which skill to fire when. I’ve done extensive testing through SR, Cruci, and superbosses to come to the conclusion that all of these skills are necessary for full optimization. Depending on what you want to do with the build, however, you could probably cut one or two. I won’t talk about all the skills used, but some are worth particular mention.
Reap Spirit: The wraiths do a lot of damage and getting it to at least 23/26 makes a noticeable difference in overall DPS.
Summon Blight Fiend: I wish this was summon Hellhound so bad. I like the dawg better and it gets way more points from gear. But to my chagrin, the blight fiend simply outperforms it. Having two of them at a time with the huge AOE taunt keeps so much trash off of you that it really can’t be ignored. It’s often enough to hold a lot of aggro from bosses as well. If you don’t play Crucible you could swap this out for Hellhound with 17/26 Ember claw, as Hellhound is good enough for SR 90. In Crucible however Blight Fiend makes a substantial difference in the ability to consistently clear 150-170.
Mark of Torment: Without it you die to Fabius/Iron Maiden in SR 90
Ill Omen: The original version of this build I tried used Hellhound instead with capped Infernal Breath. It worked most of the time, but wasn’t super consistent in terms of going off when and where I needed it to. Ill Omen is always active, and always where you need it to be. Without it you die to Fabius/Iron Maiden in SR 90.
Bone Harvest: Not unusual to see in a Necro pet build, but I wanted to reiterate the power of Bone Harvest + Guardian of Death’s Gate. The 25 reduced target’s resistances from Guardian turns bone harvest into an AOE resistance reduction that makes a huge difference in terms of clear speed.
Devotions:
Pretty straightforward pet devotion path. Between the 2 second skeleton cooldown, unstable blight fiends, and unkillable Wraiths, you can take all the offensive pet constellations without having to worry about any of the defensive ones. Hence, Staff of Rattosh instead of Typhos. The one exception is Empty Throne, which I took as it was the lowest opportunity-cost way of getting pet pierce resistance high enough. If you don’t plan on going for deep SR you can use Shepherd’s Crook instead, but if you show up to SR 90 with 70% pet pierce resistance Fabius will shred skeletons faster than Callagadra. (If it wasn’t apparent, I died to Fabius many times during testing.)
Conclusion:
This build is great for farming due to it’s high DPS and durable gameplan. Eventually any skeleton build will come face to face with the fact that skeletons are, by their very design, small and squishy. Rather than trying to fight that fact, you can get a lot done by leaning into it and making sure you’re ready to replace them as soon as they die - even when they all die at once.
