pob: https://pobb.in/XKPGKe7i0p5X

(~5 ex to get started, I'm running with probably ~15 ex gear)

#Introduction

Soulthirst is known for letting you create ultra-specialized mapping builds that abuse super long flasks to get hundreds of soul eater stacks. I decided to go self-curse to scale flask duration, as using multiple medium clusters seemed wasteful (as you can get a good chunk from just survival instincts jewel) whereas self-curse is essentially another more multiplier. Occultist was a natural option for self-curse, so next came skill choice. Naturally, you would want a skill with great coverage (spark, bow attacks) or with great utility/automation (bv, winter orb). I decided to go with phantasmal spark as it plays incredibly well with occultist; profane bloom adds way more consistency to spark's clear. I have also been eyeing phantasmal spark for a while, so was glad to knock out 2 build ideas in 1.

This version of the build is lacking quite a few easy upgrades (e.g. awakened gems, better clusters), but I figured I might as well post a guide as I have hit all the key points and further upgrades will experience more and more diminishing returns; the build as is has enough strength to do what it was built to do.

##Pros

• Fast mapper

• Fun, especially if you haven't experienced self-curse shenanigans before

• No map mods are complete bricks (though some, like avoid poison and temp chains are pretty bad)

##Cons

• squishy, will sometimes die

• related to above, definitely not completely afk mapper, will have to pay some attention

• layout dependent (though you can get through harder ones, it can definitely be painful)

• I hate grasping vines and so will you

• may hurt your eyes or crash your instance/pc

#Key Mechanics

##Soulthirst The core unique here is soulthirst. It gives you souleater during flask effect, which grants 5% cast speed per kill within 60 units. Honestly, the damage is not that relevant for clear, and the biggest advantage it gives is probably leap slam attack speed for mobility and qol on cast time. Even when you have 1000% increased cast speed, profane bloom carries the clear.

Cast speed is traditionally something occultist builds lack; most phantasmal spark builds on leaderboards I checked are running 2x profane wands with t1 cast speed, and they still are lacking quite a bit. Soul thirst fills this hole and also gives a huge boost to mobility.

##Self-curse

Self-curse is traditionally pushed all the way to 75% reduced expiration rate using self-curse temporal chains and solstice vigil to grant the last 25%, giving 4x duration of any buffs/debuffs. Stacking this is very strong because there aren't diminishing returns to reduced expiration rate; in fact, it is the opposite (until you reach the cap, which requires 375% curse effect without solstice vigil). Here is an easy example: 25% reduced expiration is 1/.75 = 1.33x buff duration. The next 25% would gives you 1/.5 = 2x buff duration (which is more an increase than the first 25%).

This is the same reason stacking max res is so powerful; the first additional point (75->76) is 4% less damage while the last (89->90) is 10% less damage. I found it hard to eke in more curse effect as is, but with better gear, I think you could easily fit in a 2nd voices cluster. You could probably cut everything below the ranger/shadow cluster as well as some damage nodes like atrophy or heart of darkness.

##Phantasmal Spark

Phantasmal spark (with ashes to get full chaos conversion) allows tons of easy ways to scale damage. Probably the best example is elemental overload, which has pretty much no downside. You also can use wrath and malevolence together extremely well. Be careful though; while things like lightning and elemental damage also scale poison, things such as spell damage and projectile damage will not.

##Mana Sustain

Mana sustain is done at start of map through eldritch battery and later completely through vaal clarity. Once you get enough curse effect on temporal chains, you can have 100% vaal clarity uptime. There isn't really a hard breakpoint as you will need some time between soul gain prevention end and aura end to regain the souls. As a side note, you can't use inspiration with eldritch battery or vaal clarity (as you need to spend mana).

#Gear

Doppelganger Guise is probably one of the strongest defensive chestpieces in the game, and it is a good way to patch up the builds shoddy physical mitigation (as well as making chaos damage laughable). You get elemental mitigation from the triple resist flasks. Other than that, you are pretty much entirely reliant on killing things fast and recovering any hits that get through using the poison mastery for 3% life on kill.

• The helm was most expensive build piece and I bought it pre-crafted from someone saying they used it for self-curse worb for 3 ex.

• Ashes with 30 quality is 50c.

• A buff effect/damage circle of nostalgia is quite cheap, and obviously nobody cares about the ele/lightning damage implicits.

• Rotblood promise 1c

• kaoms %life high life is 10c

• soulthirst with decent rolls and desirable corrupt is 20c (but the corrupt is not that important)

All the rares were dirt cheap - in the ~10c range. Chaos damage is technically better than lightning damage (scaling profane bloom), but it is way easier to find super cheap dot multi + lightning damage gear. Here is trade link I used to find my sceptres which are pretty much as good as a perfect cane of kulemak.

#Skill Gems

I'll go over the important alt qualities:

• Phantasmal spark: a must have, it is what lets you play poison spark

• Anomalous blood and sand: extremely powerful, huge projectile speed

• Divergent Herald of Agony: caps poison generically

• Divergent plague bearer: very strong, free dot multi

• Anomalous withering step: should theoretically be really good for instant 14 wither stacks... but I can't really tell if it actually has any impact. May replace with phase run.

• Anomalous increased duration: Before swapping helm this was mandatory to be able to cast aura. It is still nice to have (as wont have vaal clarity up at start of map so blessing costs mana)

I yoinked phantasmal smite from my aura stacker, but you can pretty much ignore that (and probably drop smite all together). Technically between skill effect duration and self-curse you only need to use it once every 20 seconds or so, but I forgot to use it that entire map and forget about in most maps.