Level 97 Crit Firestorm of Pelting Scion^3.25

Notes

Simulated Ascendancy
At each build point I have allocated extra passives that include a scion-simulated legacy jewel.
E.g. the hypothetical level 100 build has 128 points (123 base + 5 ascendancy) and an extra 4 used to similtate the ascendancy major nodes.

Stats and resistances
I have used surplus gear from my 3.25 settlers templar flametank; they don't balance resistances or stats properly with the LoP event scion flametank.

Prioritize life and abyssal sockets on equipment, ideally armour equipment apart from the infernal mantle, and use jewels to make up for resistance deficiencies.

Unless you can easily gain strength much higher than intelligence and like the extra life, you will probably want to make strength=intelligence in the endgame
to gain the secondary benefit of the Rational Doctrine jewel.

Use 0.3% regen nodes on strength passives and 5% damage taken from critical hits +3 chaos resistance on int passives  to balance them.


Dexterity is used for Assassin's Mark only. Use whatever level your dexterity allows.
The build has 40 dexterity base, enough for level 8 Assassin's Mark. You need 70 for level 21, and you gain a mere 1% crit multiplier per level.which gives you 13% increased critical strike multiplier.

Only aim for high dextrity if you can get it without sacrificing affixes, that could have been used for a damage affix instead.


Equipment
For helmet, gloves, and boots the chase goal is high-armour items with high life, an abyssal socket, life regeneration rate, and a high resistance; For boots movement speed as well.
For rings high life, high damage taken recouped as life - ideally a Reflected item that doesn't have too great downsides
For amulet, high life and any other useful stats - ideally a Reflected item with really high life that doesn't have too great a downside
If you can get a minimum frenzy charge craft on your rings, do so; It provides more damage than a minimum power charge enchant due to being multiplicative with the more damage your power charges provide
The ideal belt is an Elder stygian vise with great life, maximum life%, and life recovery%
For weapon, a Divinarius is always handy, but a good rare with that also has high cast speed is much better since this build is all about stacking firestorms and furthermore the increased AOE radius of Divinarius is a drawback


Firestorm of pelting main skill

Firestorm does ~11% more damage per spell level until level 30, and  ~ 5.7% more damage with each level above 30. Thus stacking spell levels until you get a
level 30 firestorm is very powerful, and it is still worthwhile beyond that.

In general, you should use Elemental Focus - Intensify - Increased Critical Damage - Spell Echo - Fire Penetration supports

You may want to replace Increased Critical Damage in two cases.

Use Concentrated Effect if you want to focus your firestorm for maximum single target damage.

Use Empower if you have high critical damage multipliers from jewels and you have a level 5 awakened empower, or a level 4 empower (or awakened) if your armour has the +1 socketed gems corrupted.
Whether it is a damage gain or loss depends on your total crit multiplier and the level of firestorm without the empower since extra levels gained up to 30 are
worth more than those gained after. Run your build with imported profile through POB to know for sure once you are in the endgame.

Awakened order of importance when shopping: Elemental Focus > Fire Penetration > Empower (if you use it) > Spell Echo


Infernal Mantle Corruption

+1 socketed > +2 AOE ~ +2 duration if you have Empower in your Firestorm link
+2 AOE ~ +2 duration > 1 socketed if you don't

This is because the +1 to Empower gives +1 to the Firestorm skill gem, so +1 socketed is equivalent to +2 to the skill gem and +1 to the non-Empower support gems.
The AOE and duration both give +2 to the skill gem, and AOE also provides +1 to Intensify.


Flasks
1. I recommend you pick 5 out of Quartz, Ruby, Diamond, Silver, Quicksilver, Granite, Basalt, and Progenesis(unique, big spenders only). Only use Basalt if you are also using Granite.
2. Ensure all magic flasks gain 3 charges when you are hit prefix
3. Enchant all flasks with used when charges hit full - you may want to trigger them on adjacent usage or when not active if you have Progenesis to give it higher uptime
4. Make sure that you have the following suffixes. It is unimportant which flask they are on
      37.5% reduced effect of curses on you during effect (or higher) - this ensures you have 100%+ reduced effect of curses on you
      Regenerate 3% of life per second during effect (Catarina craft) - I generally put this on a Ruby Flask (if I use one) since it lasts longer
5. The other three flasks should have high-tier suffixes chosen from:
      x% increased armour
      x% increased critical strike chance
      x% Increased movement speed during effect
      x% of spell damage leeched as energy shield during effect
      15% of Damage taken from Hits is leeched as Life during effect (Catarina craft) - this ensures leeching even if you are running through groups of mobs without stopping to cast firestorms



Watcher's Eye mod priority:
1. Increased Life Recovery when affected by Vitality
2. Additional Physical Damage Reduction while affected by Determination
3. Anything else useful that requires Vitality or Determination

Rational Doctrine
The best synthesis implicits are 2-4% global critical strike multiplier, increased cast speed, increased cast speed while holding a shield, and 0.2% of spell damage leeched as energy shield

Rational Doctrine and Consecrated Ground
Use a sulphur flask for Consecrated Ground until you buy a Rational Doctrine jewel or get one from Uber Venarius.
Consecrated ground provides you with 6.25% life regen  before life recovery modifiers and 62.5% reduced effecitveness of curses on you.
With at least 37.5% explicit on one of your flasks, you'll be effectively immune to all curses without increases curse effectiveness.

If you match strength and intelligence you'll create Profane Ground on enemies too, helping you to crit  but this isn't essential unless
you choose to use Leadership's Price instead of Death Rush, and I have no idea how Leadership's Price will work out in practice until I test it.

Miitant Faith build 
PERSON: Dominus to get MORE damage from power charges
NUMBER: One that does NOT change the five notables: Overcharge, Endurance, Devotion, Light of Divinity, Holy Dominion
MODS: +2% elemental resistances (18% to all) and either +4% elemental damage or +4% area damage as well (+28% damage)


Stormshroud
You need 100% shock avoidance to become immune to all ailments.  Sources:
1. Abyss jewels with chance to avoid elemental ailments
2. Boots with the Eater of Worlds implicit chance to avoid elemental ailments
3. Boots with Searing Exarch impliict chance to avoid being frozen. Only use this if using 1+2 is too hard, as it is better to use the boots SE implicit on maximum fire resistance


Megalomaniac variant
Use it if
1) You are bad at remembering to use Enduring Cry and want Enduring Composure to keep topping up endurance charges, or
2) You like the QOL of endurance charges always being built up while Immortal Cry is active
 or, more generally, for the convenience

Get a Megalomaniac with Enduring Composure and one or two other great cluster jewel passives - anything that adds maximum life% or regeneration; I am particularly fond of Peace Amidst Chaos.
Here is a link to a trade search in standard for jewels that have EC and two other useful nodes. Set the appropriate league and tinker away.
https://www.pathofexile.com/trade/search/Standard/9gMnjK4TK

Set the count to 1 for a wider selection that only has one extra. In this case you might want to exclude some of the less valuable nodes such as