[3.17] Iron Mass chaos skeletons with stacked auras // A good balance between offense and defense

The Iron Mass is the centerpiece of the build. It gives skeletons Unholy Might, Wither on hit and triple damage. To maximize the Wither effect we get 3 Skeletal Atrophy, a cluster jewel notable to convert the physical damage to chaos, as well as reinforcing the Wither stacks. In addition, there is a chaos-damage granting aura called Envy that is used.

Note: Wither effects on the passive tree do not scale with Wither applied by minions.

In most other Iron Mass builds, United in Dream, another sword that grants Level 25 Envy, is used to boost the chaos damage. However, this renders the build rather squishy. So I have foregone that sword for Aegis Aurora, basically flavour of the league, combined with Melding of the Flesh to achieve 90% all maximum elemental resistances. The Envy aura now comes from a Grasping Mail, dropped from Breachlords. It is weaker at only Level 15, but an acceptable compromise given the wonderous defenses provided by the shield and jewel combo.

Aegis Aurora works best with high Armour and ES. The ES is mostly from the Gravicius' signature veiled mod crafted on the Grasping Mail, while Armour is mostly from the Determination aura. This is also where the "aura-stacking" aspect of Scion comes in. The auras for minions are:
Determination - gives armour
Defiance Banner - gives armour
Purity of Ice - gives resistance and max resistances
Envy - gives damage
Precision - gives accuracy and crit
Vitality - for self and Guardian/Necromancer buff
Clarity - for self and Guardian/Necromancer buff
Smite - Triple damage proc and also a free aura for Guardian/Necromancer buff

While I've only run 8 auras including smite, this gave me a good taste of the power of aura-stacking. I think there is a breakpoint for reaching 100% increased aura effect, which gives
5->10% max res from purity of Ice;
8->16% physical damage reduction from Guardian (1% extra from each of the 8 auras);
some 2*8% attack/cast speed from Necromancer.
Hitting 100% is a bit tricky, but I landed on a lucky Brutal Restraint with 8% + 8% aura effect, and a nice Megalomaniac with Introspection, allowing me to drop the Champion ascendancy for Necromancer.

Note: the mastery and Introspection both only applies aura effect to you, not the minions, so the auras not supported by 21/20 arrogance can't reach the 100% breakpoint. This equates to 5% PDR and 5% attack speed loss, which is IMO not worth pushing for.

The Animate Guardian almost doubles the DPS, but is also ~20% of the budget so don't let it die to detonate dead strongboxes T_T.
Crown of the Tyrant: BiS, white socket gives a lot of added chaos and a reliable source of -10% chaos res. This alone gives ~25% more damage. (2ex)
Kingmaker: a staple for minion builds. (50c)
Doppleganger's Guise: a good defensive body (100c)
Victario's Flight: movement speed QoL. (1c)
Gloves: Rare with fire, lightning and chaos res for survivability, crafted with % chance to Intimidate on hit (Exarch implicit) (40c)


As a summoner, the most important goal in gameplay is to keep the combat buffs up. Brittle ground, and the triple damage Smite are the buffs I pay the closest attention to while bossing since they contribute massive damage multipliers.

The other transient buffs that I opted to use:
Frenzy charges from Carnage Chieftains are transient given the rapid re-summoning of the skeletons. Still I used 3 to keep a good uptime while power charges can come from Assassin's mark quality. I also splashed in 1 They of Tul for more skeleton tankiness in the form of dodge.
Carrion Golem linked with Feeding Frenzy.
Desecrate + Divergent Flesh offering for large attack speed boost.
Phasing flask for reliable Brittle ground dropping.
Permanent Assassin's mark is a nice QoL update this patch. Just mark and forget.

One thing I learned this expansion is that Fractured items go really well with the new Eldritch currencies.
For example to get the chestpiece:
Buy Mail with fracturing Envy prefix, then use essences/fossils to roll resistances until 3 good suffixes, then use eldritch currencies to add/reroll prefixes until life, then finish craft with Gravicius' mod.
Similarly, the gloves are done in a similar way but focus on suffixes first with fossils, then reroll prefixes until I hit a life roll.

Also, Divine Orbs did wonders.
The overall spending on this build:
Iron Mass - 20c
Aegis Aurora - 1ex
Melding of the Flesh - 40c
Brutal Restraint - 1ex (divine it with luck)
Fortress Covenant - 40c (again, divine it with luck)
Ashes of the Stars - 2ex (high quality and reservation roll)
Megalomaniac - 20c (Atrophy + Introspection)
Megalomaniac - 50c (Atrophy + Blessed Rebirth)
Ghastly jewels - 20c e/a (life + 1 flat phys/chaos + 1 utility, e.g. block/ailment avoid)


Rare +3 helm - 1ex (got lucky with annul for skeleton craft)
Rare Envy body - 2ex (essence rolling)
Rare gloves - 4ex (fractured base is expensive)
Rare boots - 50c (buy the implicit first, then essence craft)
Rare unset ring - 50c (Filling dex for the sword + life + res roll)
Rare unset ring - 2ex (life + chaos res)
Ichor/Embers - 2ex (a significant yet unexpected part of spendings)

AG gear - 4ex

I opted for Jun + Kirac for my atlas, so I got a lot of quality and Veiled crafts together with Kirac Harvest maps. Used them + Essences to craft most of my rare gear. This might have lowered the total cost compared to buying everything from the market. Still this is around 20ex of investment.

Some potential high-end upgrades that I did not chase:
Alt-quality gems, e.g. anomalous Defiance Banner gives 10% more Armour, phantasmal Smite gives a lot of attack speed, which is ~10% more baseline DPS.
Implicit Auras, e.g. Purity of Ice on Ashes of the Stars, Determination on Aegis Aurora. This frees up gem sockets and can maybe fit in Divergent Rallying Cry or squeeze in another aura.