I played tainted pact flamewood so you don't have to (write up in comments).

I've gotten a few messages in game and on the forums asking about my build and I'm about to be done with the league so I thought I'd do some info sharing, and maybe get some ideas on how I can push the build further.

WARNING: THIS IS NOT A GOOD BUILD THAT YOU SHOULD PLAY. A finnicky flamewood build is about the least fun thing I can imagine anybody play in poe, so please don't try to emulate unless you like/want to try flamewood and don't mind racking up thousands of deaths from your own dots. I don't have a budget pob because I only started tinkering with this setup after acquiring mageblood and hitting level 100. For the showcase I removed an empower 4 and a mageblood granite flask to emulate a slightly less geared character.

Pob: https://pobb.in/LUMbOiEN8sle (Do not need original sin, I had the currency and it's nice for ignoring the added ES mods on t17 maps)

Concept

This build uses the 100% of elemental hits taken as chaos/phys tech using divine flesh + 4x hunter bound by destiny + the flawed refuge. The fourth vow chest + a healthy amount of armour + a lot of pdr gives massive reductions to all incoming hits while being immune to elemental penetration.

Unfortunately 40% of ele dots are not converted, so resists still need to be capped. Rather than overcapping res for dots, I use tainted pact unique amulet to negate and heal from ele dots (since 60% of ele dmg is taken as chaos). Tainted pact recovery is unaffected by less recovery and no regen, letting those be free mods. It also enables running righteous fire and annihilation's approach for free damage and giga recovery.

Tainted pact is turned on via devouring totem, which eats corpses and leeches life. A level 24 gem (21 gem + 2 global from dark seer + 1 from glove corruption implicit) recovers 413 life per corpse, which is plenty for a long duration leech as long as our own max life is not too high. This leech is exempt from the "monsters cannot be leeched from" map mod and not noticeably affected by the reduced recovery from leech t17 mod. I tried using corpsewalker boots on merc to generate free corpses but it doesn't seem to work, so I resign to manually casting unearth and using CWS desecrate for corpse generation. The unearth ended up being a bonus rather than a downside this league thanks to the caster mastery being soft required to farm abyss hoards.

Devouring totem needing to be permanently active means it's the primary skill alongside flamewood support. There are plenty of resources on youtube if you want to just learn about flamewood. Typically flamewood gamers use rejuv totem, since you get access to much better black zenith corruptions (+2 aoe, +2 aura), but devouring totem has the exact same hp scaling and can still make use of +1 gems corruptions for slightly less damage.

I get overleech by reserving life with petrified blood. This enables pain attunement and bloodnotch/immutable force combo as multihit defense (emiracle has a pb/bloodnotch guide on youtube if you want to learn about this), which then enables arcane retaliation notable for 25% more damage. 100% ele hits taken as chaos/phys also means no cold crits as a side bonus.

To supplement clear, I use a 6 link CWS dd of scavenging. It's kind of awkward that dd competes with devouring totem for corpses while also benefiting from none of the spell dmg multipliers in the build, but I couldn't find another skill that did any amount of damage in juiced t16.5/t17s, would love suggestions for a better skill to use here.

Having a high amount of pdr is crucial since the phys dmg taken is the normal amount + 40% of elemental. I'm using a xibaqua glorious vanity with 4 automaton studies in its radius (only taking 3 for 10% pdr), 8 endurance charges = 32%, 10% from annihilation's approach, 5% from delve helmet, 8% from determ watcher's eye, and some conditional pdr in the pantheon. Pdr is immune to map mods, but not altars, so I run exarch instead of eater. Some of this you can give up and still comfortably clear t17s, but I don't know how much.

Fourth vow over doppelganger's guise because doppelganger would reduce the healing from tainted pact, requiring more investment into max fire res. Same reason applies for why I'm not overcapping chaos res. Since endurance charges ele dr applies to dots, you technically can easily get at least 6% max chaos res without upsetting the tainted pact balance, but I like the big differential for more healing against phys dots, and I couldn't be bothered hunting down the perfect megalomaniacs for the build. Overcapped res also gets knocked down significantly by -max map mod.

Merc is just a shock ambusher with zealotry scaling, abhorrent interrogation+blackflame to apply some wither, and garb so t17 maps are playable.

A small of list of reasons why you shouldn't play this build:

• devouring totems need a bit of time to arm before a corpse is consumed, meaning while approaching flames is turned on, any time you zone into a map or forget to feed corpses to totems or spam summon totems too quickly, you instantly start taking big dots and will very likely die. I run a life flask to counter moments of forgetfulness, but flasks heal you above petrified blood low life which then turns off your overleech, giving another window of massive degen before your totems eat a corpse. This is especially frustating on maps with super high -max, and could lead you to dying over and over

• despite being tanky enough to face tank uber shaper and stand inside sirus storms, I still cannot tank volatile cores in most maps, and awakener's desolation/searing exarch runes are extra miserable since the build is low life with no energy shield. For whatever reason ggg also gave totem players a middle finger with the 15% totem dmg taken to summoner modifier, which has to be rolled over (it's not too bad if spawned via risk scarab without map mod effect)

• flamewood totems are not only omega clunky and slow, but is unviable for a LOT of farming strategies. Everywhere in the game there are monsters that don't like attacking your totems (such as the stygian spires in the showcase video). Drox and elder are both undamageable in one of their phases. Blight is straight up impossible. Abomination map boss can be miserable since you don't control who your totems kill first, and if shavronne is the last of the trio left alive, most of her attacks do not proc flamewood while you are getting nerfed by doedre's constructs

• because the amulet slot is taken by tainted pact, we don't get to use defiance of destiny, making monster attacks that don't stun such as t17 ball lightning constructs very dangerous