Character Window
Stats shown with passives and Hungering Void active. Sheet DPS is Stun Jacks.
Grimtools
Affix-less MI setup: https://www.grimtools.com/calc/qNY5pyBN
Setup I use with self found MIs: https://www.grimtools.com/calc/eVLdjx5V
Probably BiS setup: https://www.grimtools.com/calc/gZwmopk2 w/ max slow resistance crafts on amulet/medal.
Introduction
Feel free to skip, mostly exposition.
Chaos Pyromancer caster was by far my favourite character that I built, played and posted all the way back in vanilla 2.5 years ago when I was a worse theorycrafter. Since then it’s not something I have ever revisited until recently. I don’t know why but I decided to try put a GT link for one together about a week ago around Stun Jacks, it needed some pretty hard-to-get gear but by the end the stats on it looked solid so I went ahead and levelled it. I was expecting it to be pretty average at best like most of my bizarre builds but it came out surprisingly well, enough that I decided it was worth sharing.
I’ll say this as well - I’ve seen a couple of posts over the years that some people have wanted to make a build around Chaos Bolts but haven’t been able to due to it being too weak/not scaling well at end game. If you’re someone that has tried and failed, this build may appeal to you as it has a similar feel and is very much viable, and yes the GFX on Stun Jacks does change 
Now, with all that said. Lets get into the build properly.
Build Concept
- Stun Jacks is our main source of damage through the Conduit fully converting it (bar DoT damage) to Chaos.
- At point-blank, all of the projectiles fit into an enemy shotgunning for huge amounts of damage. This also makes it an insane proccing machine for Twin Fangs enabling us to sustain on our main attack.
- Because I had around 6-10 gear slots to fill after putting key items for Jacks in, I went with pure Chaos Sigil.
- Sigil of Consumption helps on the AoE front and provides extra survivability through life steal.
Abilities
Stun Jacks (Twin Fangs): Main source of damage.
Flashbang (Hungering Void): Provides DA strip and a chance of fumble/impaired aim.
Thermite Mine: Provides chaos resist reduction.
Sigil of Consumption (Raise the Dead): Secondary form of damage and sustain.
Blood of Dreeg: Provides OA, health regen and physical/acid resistance.
Solael’s Flame (Eldritch Fire): Provides chaos resist reduction.
Ravager’s Deathgaze: Provides chaos resist reduction.
Displacement: Allows easy and fast manoeuvrability.
Pet Attack: Command your Skeletons to focus their resist reduction on one target.
Flame Touched: Provides OA and DA.
Vindictive Flame: Provides % total speed.
Solael’s Witchfire: Few nice buffs for 1 pointers.
Possession: % Damage absorption, % skill disruption resistance, % chaos resistance and chaos damage.
Severed Faith: Aether resistance, increased healing effects and chaos damage.
Presence of Might: Physical, pierce, bleed and vitality resistances.
Resist Reduction
Eldritch Fire: Provides -35% chaos resistance that spreads to nearby enemies.
Thermite Mine: Provides -46% chaos resistance in an aura around the Mines.
Solael’s Flame: Provides -10% chaos resistance as a debuff.
Ravager’s Deathgaze: Provides -10% chaos resistance as a debuff in a nova centred on your character.
Voidheart: Provides -10% chaos resistance on a chance of critting.
Combustion Band: Provides -8% chaos resistance on a chance of attacking.
Raise the Dead: Provides 25 reduced target’s resistance on the Skeleton’s attacks.
In total, this is -119% chaos resistance and 25 reduced.
Attributes
Couple points into Spirit for our off hand, rest into Physique for much needed health/DA.
Gear Options
- Craft your Conduit/Badge for % freeze resistance, % slow resistance, % reduced stun duration or % armour.
- Similarly, try to get affixes on your Valdaran shoulders like Demonic, Consecrated, Stonehide, of Kings, of the Void Harbinger for the above stats.
Devotion
- Guardian’s Gaze can be used instead of Twin Fangs. In large enough crowds (like in Crucible) and with enough eyes, i imagine this will outperform Twin Fangs. I chose Twin Fangs as it’s good for ADCtH immediately (don’t have to build up eyes) and it should life steal more on single targets.
- Tree of Life is taken to cover energy management. This build has no problems at all with spamming Stun Jacks.
Playstyle
Lay down Thermite Mines, debuff with Flashbang, Solael’s Flame and Sigil of Consumption, then spam Stun Jacks in enemy faces. Keep up your debuffs and Sigils, use Ravager’s Deathgaze to speed up Heroes/Bosses.