Level 96 Holy Flame Totem of Ire Ascendant^3.25

Notes

Build from guiorioli, and thanks for  Tatiantel2 (www.twitch.tv/tatiantel2) for all the help with the build as well.

Link to this build in PoE forum -> https://www.pathofexile.com/forum/view-thread/3146104

This build is based on the interaction between Scion's Chieftain and Hierophant ascendancies, giving her +1 Totem, a lot of fire damage (with 'covered in ash').
It also takes advantage of Holy Flame Totem's skill description, which deals Physical Damage and converts to fire, so we can use some tricks to get extra damage.

About Holy Flame Totem of Ire vs regular version

Holy Flame totem of Ire has a cast time of 0.18s, while normal HFT is 0.25. 
This means (0.25-0.18)/0.18 ~= 0.39 = 39% more damage.
My suggestion is to play with regular HFT until you get quality on HFToI, which will help make mapping easier without the 2 extra projectiles.
You need to either farm labs or trade for HFToI, no way to get it in vendors.


How to use this POB:

This POB got different loadouts, which are switchable in the top right dropdown box. 
 - Basic build is composed of easily obtainable/craftable gear
 - Trade build may be easier to pull in trade, with uniques, and easier to scale dps
 - Trade high-end is just a experiment on what one can do with a lot of money

Leveling:

Switch loadouts (top-right corner) for each act to see items, gems and tree progression for a basic HC SSF viable run.


Crafting basic gear:

Shield
Get a str base shaper influenced shield - you can get any influenced shield and reroll the influence to shaper in harvest. Both Rog and Gwennen can give influenced shields.
Spam Essence of Loathing until you get % phys damage reduction (and preferably some other good suffix). 
Craft "suffix cannot be changed" and use harvest craft "Reforge an Influenced Rare item with random modifiers, including a Influence modifier".
This will add +1 totems guaranteed, since it's the only possible prefix. Craft life.
An easier/cheaper but less tankier version would be just spamming Essence of Loathing until you get +1 totems, not caring about %pdr.
Or rolling reforge physical on harvest and not getting %block.

Wand
Get a ilvl 2 Driftwood Wand from Act 1 "The Coast" area.
Use essence of misery until you get +1 level of all fire spells or +1 level of all physical spells. (ilvl 2 has very high chance at it)
Craft increased spell damage.
Easier/cheaper with somewhat less power: get a Pagan wand base, use essence of misery and craft increased spell damage.

Body Armour
Spam "physical" harvest on a DEX/STR base until you get both %phys reduction and a good suppress roll. 
If you hit life or life regen, you need to either remove the mastery "15% increased life if no life on body armour", or annul it, or start over.

Rings and Amulet
Spam essence of Zeal until you hit good life, craft +1 endurance charge obtained from Jun unveils.


Explanations:

Returning Projectiles support
You need 40% increased projectile speed along with a 20% quality Holy Flame Totem of Ire in order to use Returning projectiles support
and get its projectiles to return, which is the best possible support with 39% more damage. This isn't that simple to achieve alongside the
dexterity requirement, so I'm leaving this to the higher-end versions.

Mana Sustain
This build uses a lot of auras (as most builds do these days). Having the mana to sustain their reservation and totem cast cost may be tricky.
Before you get all reservation and mana nodes, you'll have to choose which aura to use, but, as a general guideline: 
 - always have Herald of Ash, for it's too much damage to pass.
 - I tend to always have some level of clarity and vitality during campaign, makes things easier. 
   You don't need to level them to max, at ~level 6 they are already pretty useful
 - Use Inspiration support, it greatly reduces totem mana cost and is just a small loss of dps compared to other options
 - Picking the Life Mastery "Skill cost Life instead of 15% of mana cost" 
   This makes a skill that costs 100 mana, for example, to cost 85 mana and 15 life instead.

Arcane Surge
Ascendancy makes Arcane Surge grant 10% more damage. This means that nodes that increase AS effect also increases this.
We get Arcane Surge (level 1) from hitting enemies, from Hierophant ascendancy. 
It's still worth it to use a higher level Arcane Surge gem to get a bigger effect, if slots allow this.

Exposure/Mines
Wave of Conviction applies -15% exposure. Before Ancestral Bond, use it as self-cast.
After you get Ancestral Bond, it deals no damage as self cast. This is why you link it to High-impact mine (which also gives some extra damage)
Then, we take advantage of Charged mines to have Frenzy charges, and of Combustion to apply more reductions to fire resistance.

Flame Wall
Holy Flame Totem fires projectiles which go through Flame Wall and get added fire damage.
Arcanist Brand is a nice way to grant that the enemy will always be inside a flame wall

Physical damage, Herald of Ash, Fire conversion
Holy Flame Totem deals Physical damage and converts 50% of it to fire. So, additions to both fire and physical damage works.
Herald of Ash adds damage based on physical damage, so it gets the entire Holy Flame damage (which is physical) and adds more. It's a huge boost in damage.
Finally, we convert all damage to fire through Avatar of Fire, so that all damage is boosted by increased fire damage

Shaper Shield
A shield with Shaper influence is the only way to get 1 extra totem, being BIS for totem builds.
Ways to get it range from Expedition (Rog and Gwennen), Harvest (reroll influence) and shaper scarabs.
If you are in Trade leagues, you can usually buy a base for cheap and roll with influences, or buy a finished one.

Wand
It's easy to get +1 fire on act 1 wands, the ones you buy as soon as you get to town, at level 2.
A +1 wand -> aug -> regal -> craft cast speed is enough for the entire campaign.
If you don't get one, good increased spell + cast speed are good enough too
In endgame, I use Heathen wand because Profane wand requires too much Int.

Chieftain
Chieftain is a good ascendancy for HFT for the fire damage, str and covered in ash, which is 20% more damage and slows enemies for 20%.

Physical to Elements conversion
Converting incomming physical damage to any element is a great defense against phys, since the damage will be mitgated by 75%+