[3.8] 2M++ Flameblast Ignite DPS! Ignite your way to Uber Elder!

Self-crafted staff - Choose a ilvl80 ELDER staff (NOT Warstaff) with attack block implicit and alt+regal for these 3 mods:
Prefix - Socketed gems are supported by level 20 Inspiration support(1st priority)
Prefix - +3(or 2) to level of all fire spell skill gems (2nd priority)
Prefix - + 66 - 75% to fire damage over time multiplier. (Third Priority)

As you can see, all three mods are prefixes, so alt and if you get a suffix, augment, if you get a trash prefix then alt, if you get one of the prefixes aforementioned then regal. Alternatively, Chaos spam.
Suffixes do little to the build so I won't touch on them. I spend around 30 chaos spamming for the DoT multi and inspiration support, then crafted +2 support for 2ex since there was an open prefix. YMMV.

The most important mod is the inspiration support gem. Due to the nature of flameblast you are permanently at 5 charges and its a additional multiplier to your damage. No other mod beats having an addition support gem that cost lesser than or equal to your six link.

The next most important mod is the +3 to fire spell gems. It grants a huge boost to damage since we have little to no added fire damage to spells. However, not having this mod is replaceable with a +2 to level of support gems and replacing burning damage with empower. Slightly lesser damage but more expensive (lvl 3/4 empower) but it does grant +1 radius to ignite prolif, which increases clear.

Lastly is the fire damage over time multiplier. Its good but not irreplaceable. Crafting bench gives up to 40%, mod gives up 75% but its readily available on many pieces of gear and tree. Weapon is the most important part of the build contributing ~ 50% of your dps

The searing touch is a very cheap weapon that does pretty decent damage. You do lose around 500k ignite dps if you stick to the searing touch. At 1.3m dps you can still do uber elder pretty comfortably with it.

Rest of the gear are as follows:



I opted going the blasphemer's grasp route, so force elder bases into my build. With 8 elder items currently I have about additional 32% DoT multiplier and 64% increased shock and chill effectiveness and 48 life. Its a really good use of a glove slot.

I highly recommend the "70% increased mana regeneration while you have casted a spell recently" enchant. With a level 13 clarity, I can swap out my mana flask with 0 mana regen nodes on the tree. Awesome stuff.

Improvements to gear: I would swap out my non elder ring to one with more resists so I can craft " 30% increased effect of non-damaging ailments" on my boots"


FLASKS



Panicked life flask with stanching is a must have followed by an adrenaline quicksilver flask. Rest is up to your preference.

I would use a Cinderswallow flask since it provides so much dps, swapping with my mana flask. Will also use a high rolled Rumi's since we have some block chance and why not stack it. Divine flask for extra damage/regen. Quartz flask would work too.

JEWELS


Watcher's eye with fast DoT provides a multiplier to your overall ignite damage. Must have.
I went with an abyss jewel for added cold so my orb of storms will be able to chill. Phase chance to deal with annoying mobs in delves.
Rare jewel with life/fire DoT multi/fire damage/Damage/Burning damage

I would add a lethal pride with 10% faster ignites if I can. Elusive and expensive, I wouldnt really worry about them until they are the last piece of the puzzle.

Last but also important note: Do not take any added fire damage to spells. It will screw up your EE.

Weapon(6L)
(if +2 support gems is crafted)

Golems

I used these in my helm with a Minion life mod.

Orb of Storms/Flame dash

Squeezed OoS with Flame Dash due to lack of sockets. Would add PCoC inside if I had the sockets

Auras


CWDT offering/SR totem

CWDT offering for Cinderswallow charge generation, SR totem for fire exposure

Just level with your favourite spells and take generic spell damage nodes or elemental node then respec. I personally used ball lightning with a Agnerod West and a trash 5l armour. Completely rekts the story acts.