[0.4] Iron Ward Infernalist with Rat Cage.. who would have thought?

Iron Ward received a considerable buff in 4.0, specifically a ~300% damage and AOE increases.

This build relies on a combination of Infernalist's Pyromantic Pact and The Rat Cage in order to automate Iron Ward and push it closest to being a reliable proactive skill.

This combination is a dangerous game for our character's survival, so we do our best to mitigate all the roadblocks it creates.

A little T15 mapping showcase so you'd get an idea:

https://www.youtube.com/watch?v=6biC_qBoXbM&t=3s

So how does it work?

Iron Ward is a Spirit skill that accumulates reduced Physical damage up to a set amount, determined by the gem level. You can later release that damage in a huge nova by using the skill.

Pyromantic Pact is an Infernalist's ascendancy passive, which makes you Take Fire damage when reaching maximum Infernal Flame. Two things to consider about this passive:
- Infernal Flame is a replacement to mana and equals x2 your mana pool.
- Damage taken is treated as a Hit and the amount of damage equals your total life and ES combined.

The Rat Cage is a unique EVA type body armour that converts 100% damage from Fire Hits into Physical Hit damage. Which means that Pyromantic Pact now deals Physical Hit damage to your character on reaching maximum Infernal Flame.

The implications

This interaction creates an opportunity to actively fuel your Iron Ward by churning your Infernal Flame, but It also creates a handful of problems to solve, namely:

1. The Rat Cage only affects Hits. We still take Fire damage from DoT (Ignite; Non-Ailment DoT).
- We go for Ignite Immunity via Crystallised Immunities notable since we also use Grinning Immolation ascendancy notable, which heavily ignite us on criticals.

2. Pyromantic Pact makes us take a BIG Physical Hit. Armour is rather bad at mitigating big Hits.
We'll need a combination of Armour and PDR to minimize self-harm, and Life Recoup to stay alive:

- The Hollow Mask, Tawhoan Tower Shield and corrupting The Rat Cage solve PDR.
- Iron Reflexes, Scavenged Plating, Guatelitzi's Thesis augment and notables solve armour.
- Taut Flesh, Endured Suffering, Made to Last solve the unconditional Life Recoup.
Summon Infernal Hound + Romira's Requital Lineage Gem helps while the Hound lives.
- Pliable Flesh, Estazunti's Soul Core of Convalescence augment and Heart of the Well with a right mod solve the Recoup Speed.

To reliably churn Infernal Flame in order to store damage for the Iron Ward, we'll need to either:
- Reduce our total Mana (which in turn reduces Infernal Flame);
- Maximise the Cost of our skills used for churning.

Our end goal is to activate Pyromantic Pact's damage with a single use of a skill. Lets call this skill an enabler. Simply speaking, we need our enabler to cost 'N' InFlame while having 'N' InFlame in total.

In order to achieve this:

- We grab Eldritch Battery Keystone, which doubles the Cost of Skills.
- We grab Vulgar Methods and Brute Strength notables to reduce our maximum Mana aka InFlame.
- We grab Barbaric Strength and annoint Overzealous the notable to raise the Skill Costs.
- We choose Bone Cage as our enabler since it can use all support gems with the highest cost multiplier: Unleash (50%), Spell Echo (50%), Magnified Area II (30%).
- Raise the level of your spell skills through Hedgewitch Assandra's Rune of Wisdom and explicits on your Wand and Amulet.
- If you are still in Campaign - you can skip the permanent 5% maximum Mana increase.

You can see in the mapping showcase video (link above) - it takes Bone Cage's use time (around 0.6 seconds with my setup) to prime the Iron Ward for the screen clear.

Recommendations

1. It is recommended to have between 2.5 and 3 thousand HP. You take around 20% (if Summon Infernal Hound is active) or 25% of your total HP per cast, but the Life Recoup refills it in lower than 4 seconds.

2. Do not be afraid to spam Bone Cage, since Guatelitzi's Thesis socketed in The Hollow Mask will ramp up our armour with each cast. This augment alone can pump Armour from around 14k to 21k in seconds. Recoup regen gradually goes up to 1000+ per second, though you might need one use for a kickstart.

3. Against Bosses you ramp up your Iron Ward meter to 100% while hitting the boss with Bone Cage. Socket Armour Break III and Uruk's Smelting Lineage into your enabler and fit Exploit Weakness and Bleed III into your Iron Ward.
Set the scene with Entangle, Thrashing Vines and Thunderstorm against Bosses as seen in the showcase video.

4. Socket Pin II into your Iron Ward to make it Pin enemies, then take Rusted Pins to aggravate the Bleeding on pinned Rares and Bosses. Rusted Pins is poorly positioned on the Skill Tree, so reaching it with Controlled Metamorphosis is preferable, since it also opens up Momentum notable for 8% extra movement speed.
The bosses are very easily pinned since with Pin II and Rusted Pins we get ~+400% buildup.

5. Due to The Rat Cage we do not need Fire Resistance.
I am sitting at negative 63% right now.

The result

The result is a fantastic clear build for T15+ maps and an above average ability for bossing, but hopefully fresh enough to re-ignite (pun intended..) POE 2 passion for some.

Strengths

+ Iron Ward clears screens.

+ Have active control of Iron Ward's damaging component. It can be filled to 100% in seconds.

+ You can comfortably sit at negative fire resistance, which eases the RES capping.

+ CAN TANK MONKE aka Mighty Silverfist.

Weaknesses

- Boss damage is OK but not great.

- Degen ground / aura is dangerous.

- Can die to non-ignite fire DoT, which is extremely rare, but it DOES exist. Digsite area's book holding mob is our arch nemesis...

This build is costly since it requires very precise items, also the old forum format is not great for showcasing the items and skill tree, therefore I leave a Mobalytics link: https://mobalytics.gg/poe-2/profile/dc16e6ea-5919-43a7-b675-ba99cbefe9f3/builds/d4c2896c-28c9-4c15-95b7-12f90348c39d

Enjoy :)