I've been working on an AG build this league and it's been pretty fun to optimize. I'm sharing where it's at so far.

Path of Building

• https://pobb.in/kVYNzG-XQsAk
• Note there is a separate "item set" for the AG

Videos

• T16 Minotaur kill
• T17 Fortress
• Uber Shaper last phase

Summary

The build scales damage by turning the AG into an armor stacker. We scale auras on the player and use Pyroclast Mines for flat damage.

Overall the build has strong offense and defense, but can be a bit challenging to play, with several buttons that need to be managed, reliance on minion AI, and a theoretical possibility of losing your AG (though we'll talk about that later). It can also be challenging to build, with multiple gear sets and many different interactive mechanics at play. It is very rewarding though, as there are a lot of optimizations and improvements to make over time, and the sheer novelty is fun. It's viable for doing most endgame things, even on a relative budget.

Offensive Mechanics

Increased Damage

• AG has a lot of base armor (40k at gem level 33)
• AG uses The Formless Flame for Increased Armour per overcapped Fire Resistance
• Player uses a juiced up Purity of Fire, Purity of Elements, Defiance Banner (with Rallying Icon notable), and other things, to give the AG roughly 700% fire resistance (and thus Increased Armour)
• Player scales that armour further by using Determination with high aura effect (123% more armour in current POB) and flasks via Ceinture of Benevolence
• In the end, the AG has >1M armour
• The AG dual wields Replica Dreamfeathers to turn this into more than 5000% increased damage

Flat Damage

• Player uses Pyroclast Mine of Sabotage in March of the Legion
• The levels and aura effect are scaled heavily, such that 12 mines provides ~5000 flat fire damage to the AG

Movement Speed

• Defiance Banner provides 264% increased movement speed in the current setup, which is vital to making clear feel okay with a single (melee) minion.
• As a Champion using Perfidy, this has 100% uptime

Defensive Mechanics

Block/suppress/other

• 70 block/65 spell block from the passive tree
• 100% spell suppress from Defiance Banner
• -400 damage taken of each damage type from suppressed hits, from Defiance Banner
• Significant "Reduced Damage Taken" from Champion's Fortitude and Conqueror nodes
• 10%+ life regeneration from Defiance Banner with Champion's Inspirational node
• Ailment immunity through Purity of Elements

Physical Mitigation

• 50k armour

• 3 endurance charges (from Defiant Stand notable)

Elemental Mitigation

• 90 all res from Melding of the Flesh. This is easy to do with 12 max fire res from Purity of Fire and a Ruby flask.

Playstyle

General playstyle

The skill rotation normally goes something like:

1. Link minions
2. Use convocation
3. Use banner
4. Throw pyroclast mines
5. Curse (if necessary)

If at any point you don't have your minion linked, your banner down, or your pyroclast mines thrown, you lose a lot of effectiveness. So it's important to always keep those things active.

The build shines at mechanics where you can just sit and watch Bob go to work, like Ritual, or Harvest.

Link skill

The build uses The Hand of Phrecia and Ceinture of Benevolence, which means we need to link the AG at all times. Link skills are a bit clunky, and there isn't any easy solution to this. I personally just spam the skill in the general direction of the AG during any downtime, which seems to work well enough.

FAQ

Does the AG die?

It's definitely possible, but it's only happened once to me, and that was before I had solved many of the build's problems (e.g. I was using Flame Link instead of Protective Link, didn't have Empower linked, etc). Generally it's difficult to get into a situation where the AG dies before you do, as it is far tankier than you. One of the most likely ways for the AG to die is if it gets "stuck" trying to attack something it can't reach, and thus stops leaching/killing. This will only happen if you're not paying attention and don't have your Quartz flask active, which shouldn't be very often.

It's also worth noting that none of the AG's gear is expensive (unless you want it to be). So the AG dying is more of an annoyance of having to rebuy/craft the gear, than a meaningful expense.

Why aren't you using <<some gem>>?

The build is extremely socket starved. It'd be great to run flesh offering, a second curse, vaal haste, stormblast mine, feeding frenzy, etc. But the current POB is the best balance I've found so far. You can give up CWDT+Molten Shell at your own risk.

Why not crit?

It's definitely possible to go crit. At a minimum you'd probably need a much better weapon on the Player, with additional links to Crit Strikes and Crit Damage. I haven't theory crafted it much though.

How should I level this?

Just do whatever to get to 68ish and then respec. You should be able to do this from the beginning of maps, just be careful in the beginning since your AG can die if you really mess up.