PoB: https://pastebin.com/NGgVuxiB

Budget LL starter version: https://pastebin.com/RuvGDXhf

alternate quality stuff is added to nebulis

#Introduction

Aura stacking seems to have gained a resurgence this league. Alternate quality gems have massively buffed the builds damage and also increased the survivability and QoL. Even without the ridiculously overtuned 'Purposeful Harbinger' cluster notable, simply having access to as many 6% aura effect nodes as you want is hugely powerful when scaled correctly.

Aura stacking is a great build if you want something where the sky is the limit budget wise that is very flexible in terms of setups. My setup focuses on defences and abusing alternate qualities as much as possible. If you want to nearly double the damage though, you can swap to low life.

#Mechanics The core concept of an aura stacking build is stacking aura effect (mainly from medium clusters) and auras (which you fit in by getting a bunch of reduced mana reservation). To get to 4x aura effect, you need to get 243% aura effect from your clusters. This means you need on average 35% aura effect per cluster. An aura cluster with 6 passives and no notables will give 30% aura effect, and with first among equals and 25% increased effect, it will give 38%. This means if you get 5 clusters like that, you only need 53 aura effect from your last 2. This lets you replace either first among equals or the 25% increased effect of these last 2 clusters for some other notable. I opted for 2 rmr notables (sublime form & uncompromising) to help fit in all my auras.

##Alternate Qualities

Alternate quality effects were clearly not designed around being scaled by aura effect. 4% elemental penetration is already extremely strong for a quality, but when you start multiplying that by 10.... it gets out of hand.

The reason it is important to have a +1 socketed gems corruption on your boots (or gloves, but that is very expensive on maligaros) is so that we can create a lvl 5 enhance setup for our alternate quality gems. This will effectively be a 2.5x multiplier on the effect of any alternate quality gems. Combine that with our 4x aura effect, and we get our 10x alternate quality effect. Divergent purity of ice/elements each grant 40% penetration, and divergent determination will grant over 100% of your evasion rating as armor (iron reflexes is crying).

The other alternate quality gems are no slouches either:

• Anomalous grace and purity of fire/lightning give us ignite/shock immunity
• Anomalous malevolence gives us 50% more skill effect duration than the normal version
• Divergent haste gives us 40% projectile speed which is very nice for spark
• Anomalous dread banner makes nearby enemies deal 8% reduced damage

Other than that, there are some decent skill/support gem alternate qualities, but none that stand out nearly as much. Divergent faster projectiles is a minor improvement, and both the spark alternate qualities are nice. The pierce one in particular is good to run before you get awakened fork.

##Survivability

The build has:

• 90% all res
• Chaos damage immunity
• Ignite/shock/freeze immunity, 50% chill avoidance
• 90% physical damage reduction. As in for the largest physical damage hit we can possibly take (which is 10 * our health pool of 5k), our armor is sufficiently high enough to bring our physical damage reduction to 90%. This requires 125k armor, while we have 172k. Calculations sourced from wiki formulas.
• over 1k es regen/second
• 94% evade chance

I tried to fit in an aegis aurora, but it would lose me a lot of damage, and I feel sufficiently tanky.

#Gear

https://docs.google.com/spreadsheets/d/11914yS2Zc6dgfuVXmx7XeAws6AQakcbn6CuNI-J9AeY/edit#gid=0

If you were to try to copy all my gear this instant, the estimate would be ~116 exalts. I spent less than half of that though due to buying when things were far cheaper (bought all my aura clusters in first week for 5-10c each and I got alt qualities for half of what they're at now).

I would recommend having at least 50 ex before you start if you start. Alternatively, you could start out as an aura bot which has vastly lower requirements. The basic gist of it is to socket your 3x purities in a +4 alpha's howl (can be lvl 21 vaal purities inside a +2 duration for even lower budget). This will make it so you only need 3x aura effect to cap all res. Other than that, use a victarios influence and socket your damage auras in there and throw es gear everywhere else.

Make sure to get a lvl 21 smite and socket it into your +4 alpha's howl alongside discipline. Those are the two auras it is most beneficial to give +4 levels.

##RMR jewels

Do yourself a favor and don't bother with % es rmr jewels until you have upgraded pretty much everything else. 20 int jewels give you 50% of the es for 5% of the cost (20c vs 400c). I would definitely say though get the int jewels over random trash rmr, it is well worth the relatively low cost. Also, I have a fertile mind on the bottom right of tree which you can swap for intuitive leap to save 2 skill points.

##Saqawals I would really recommend paying the extra currency to get a very well rolled saqawals (70+ attributes, 140+ es). It only costs ~150c more than just buying one with bad rolls, but it will give you more extra energy shield than upgrading a trash jewel to a % es one (which would cost 300c+). Also, hillock 28% qualitying it is very nice since the chest has no local % es. Getting some white sockets with vorici is also good qol to be able to swap skill gem setups whenever you want.

##Prism Guardian If you have 75 rmr, you can use prism guardian even if you are CI. This will require 9 rmr jewel corruptions on top of the standard rmr from saqawals/amulet/alphas howl/tree. I would say go with prism guardian unless you have a really insane shield with socket gems have rmr and also one of: aura effect, a sizable amount of damage, very high es.

##Gear Corruptions

+2 corruption on alpha's howl and the +1 on boots. These two are massive for the build. You could get a discipline corruption on your shield to save a skill gem slot (which I would use to add in an offering skill or molten shell). +1 socketed gems or +2 aura/aoe also would be good, but are not a really cost efficient upgrade.