[2.1] Dual Apep's Chaos Crit - Stapling Chaos to a Level 1 Spell (Draft Spark Totem tree up)

Pros:
-Damage: I'm doing 112,500 shotgun dps. Clear speed is pretty fantastic even in high maps.
-Mana Cost: My main spell has a base cost of 4. Even in a 6L with +80% cost from items, it is no problem. This leaves me free to devote my mana pool and regen to defense.
-Gear versatility: Other than the two Apep's and some unique gloves, the gear is pretty open. I can see how either an ES chest or a hybrid chest could get there. The level of AA can be tailored to the gear's capacity. I ran one in the high teens and did great.
-Skill Versatility: I use Freezing Pulse, but small changes to this build make completely different skills work. You can use Ice Spear instead. Switch Sniper to Blast Radius in the tree and do Flame Surge, Storm Call or Glacial Cascade. I think FP is the tip of the iceberg for lvl 1 chaos crit spells. I've played around a bit, but I like Freezing Pulse best.
Easy to level: The tree works fine as a regular FP crit Witch until you swap over to chaos and a mana-based defense instead of offense.
No tree swap at high levels: You change your gear rather than the tree in your 60s to swap over. No regrets or respec points required.
-Map versatility: Blood Magic, 50% Regen, and No Regen are the only ones I'd suggest avoiding and I think that 50% Regen is doable sans AA. Both reflects are fine, but I like to turn off Herald of Thunder during Elemental reflect maps.

Cons:
-Upper limit on base damage: The base chaos damage of your spells is limited to the best Apep's wands you can buy and a lvl 21 corrupted Added Chaos gem. You can scale it to your heart's content, but it puts a pretty hard limit on this variant's base damage before that. Any more damage you add (and I do a bit with Herald of Thunder) must be elemental, which opens you up to relevant reflect numbers. Ths build deals well with the low base damage ceiling (112K shotgun dps!), but you need to be aware of it.
-Positioning: FP makes you want to stand close. Lightning Warp helps a ton, but at the end of the day, you're doing your best damage at close range.
-High link dependent: This build really wants a 6L and due to the mana-based defense, using Tabula Rasa doesn't really work. You can do this in a 5L, but won't be able to leech as effectively using only curses and Atziri's Promise without losing a huge pile of damage. Removing a dps gem cuts about 1/3 of the damage I deal.
-Weak to Elemental Spikes: Repeated hits from elemental sources (that get around Immortal Call) are the most dangerous thing. Especially when opening a box or fighting dischargers or caster Exiles, you have to be careful not to get overtaxed by elemental damage.
-Weak to Corrupting Blood: You can easily pick up 20 stacks of off-screen Corrupting Blood from GMP Freezing Pulse. MoM/AA does not do a thing to fight degen. Your reaction time to it if you stop leeching needs to be very quick. (The 1.3 flask changes help a ton here. A Surgeon's Divine Flask of Staunching does a lot of work now that it grants immunity during the effect. Having a non-instant flask largely solves this problem if your reaction time is okay.)

I needed to build a tree that would focus on generic spell damage, chaos damage, projectile damage, and crit while still getting as much life as I could. I also needed a way to defend myself while dual-wielding wands. I took a page out of the staff caster book and grabbed Mind over Matter (in the tree), Arctic Armor and Eldritch Battery. I don't need to worry about spending too much of my mana on casting spells, so I have a bit more leeway here than most do. As long as I was going right past it, I picked up Iron Reflexes for use with Grace to give myself some armor that did not rely on my gear. Going to this part of the tree gave me access to some great life nodes as well as Profane Chemistry, a node that I have huge respect for. I rounded out my tree with as much mana and mana regen that I could get my hands on efficiently.

Tree:
https://www.pathofexile.com/passive-skill-tree/AAAAAgMABUIHHg5ID8QRlha_JpUppSycO3xBlkSrSVFMs04qUDBVS1WuVcZd8l8qYeJjQ2-ecFJw1XcHf8aCEIIegwmD24cTidOPpo_6lS6cpKKjrrO4ysHz0PXbC9te37Dr9fDV8h3DCbmTAx4fQQQH6-QRD0wtiig740T7ZAnqYs2YjX62QXXLvTZlTb6n1fjfirVIBiMqC_PqykpRTKxHfVsqTaQ50IFH4iLiFSAs6W5pwzqbtVM1D6uTH-ZYieBJE90NW6-VIC0faxdqQ8BUvOoI9IUydPEY20p945-Hdmeg_MXA40tX8bM=

Builder:
https://poebuilder.com/character/AAAAAgMABUIHHg5ID8QRlha_JpUppSycO3xBlkSrSVFMs04qUDBVS1WuVcZd8l8qYeJjQ2-ecFJw1XcHf8aCEIIegwmD24cTidOPpo_6lS6cpKKjrrO4ysHz0PXbC9te37Dr9fDV8h3DCbmTAx4fQQQH6-QRD0wtiig740T7ZAnqYs2YjX62QXXLvTZlTb6n1fjfirVIBiMqC_PqykpRTKxHfVsqTaQ50IFH4iLiFSAs6W5pwzqbtVM1D6uTH-ZYieBJE90NW6-VIC0faxdqQ8BUvOoI9IUydPEY20p945-Hdmeg_MXA40tX8bM=

Bandits: [Oak/Kill] - Kill - Alira
You can get 4% cast speed in the tree very easily, so no on Cruel Alira. I wouldn't respec it, but I think it's a little better without.

Notes:
Life - This tree has 143% life. Two points can be added near Bravery and Cruel Preparation to make it 153%, but anything more requires a sizable change. If you want more, I recommend adding the previously mentioned points, removing Heart and Soul, Hired Killer, and Thick Skin for the wheel of life, and then add more from those that were removed. Heart and Soul is great for this build, but super inefficient, as connecting up over the top near EB is so much better. Keep in mind that this variant uses MoM, which sends 30% of the damage to mana.
Cast Speed - I imagine that you've noticed that there are tons of great cast speed nodes RIGHT THERE. There are, and you should take them if you can afford to cut defensive nodes or if your gear makes them better than the Method to the Madness nodes, for example. I discovered that they were worse for me and the gear I wanted to use, but that will not always be the case. Remember that more speed = worse regen while attacking. We want the regen to be awesome even while attacking to account for MoM. Try it as is and add speed to taste. Dark Arts is a bit suspect now that the pathing is not running through there, so it may be better to take Nimbleness and the Shadow cast speed nodes through Trickery instead.
Crit - Don't cut any crit. Seriously. The crit ties it all together and is the main damage factor. It's much better to skimp elsewhere.
Damage - Avoid the temptation to take any damage nodes that do not help the chaos portion of the damage, as it is basically all of it. Elemental Dominion and to some extent Trickery get a pass due to the other bonuses and the fact they are pathing nodes for us. (Trickery is not in this version, but you should take it if you can. It was the last cut.) The last node in Fury bolts and the Scion starting Spell damage nodes are reasonable too if you need more increased damage. Pathing to Ballistic Mastery gives another 20% projectile speed and opens some more projectile damage, but I have no earthly idea what to cut for it and I think cast speed would be better anyway.
Mana Regen - This tree has an absolutely insane amount. You can get even more, but I'd suggest just using Goldwyrm and/or jewelry. Most of this regen will go toward keeping you alive, so don't skimp.
Mana/ES - If you ditch Method to the madness, consider repathing near Conduit instead of down from Coordination to get Foresight for 2 points. If you choose not to take Heart and Soul, or just need more raw mana, take Soul Siphon.
Mind over Matter - You could go without this keystone for this variant and hugely cut down on mana and mana regen, but the defensive benefits seem worth it. Alternatively, you could cut MoM, keep the regen, and take all the cast speed in the tree that you can get your hands on. This would skyrocket your damage, but I don't think that you'd be able to survive very well at high level maps.
Eldritch Battery - Someday I'll make a non-EB, non-AA version of this build that uses a regular-sized mana pool and a dual Apep's lvl 1 6L with other defensive benefits like Acrobatics/Evasion/Ondar's. Today is not that day. You need EB.
Shock Duration - If you are having trouble shocking enemies, take the 30% shock duration node near EB. Getting your enemies over the .3 second threshold is imperative to getting Herald of Thunder going and getting that 50% more bonus. Also, shocks beget more shocks as your next hit will deal more damage. There is another 30% shock duration node in the Breath of Lightning wheel for two points if you want even more. if your shocks are stuttering, this is maybe the most effective damage investment of 1-3 points you can make in the tree.

These offense numbers are with 6 power charges and Level 20 Herald of Thunder active. I also use Assassin's Mark, so the effective crit chance is more like 70% against most enemies. Most enemies are also not very resistant to Chaos, so penetration is only missed rarely.

Pros:
-Damage: I'm doing over 200,000 shotgun dps with Atziri's Promise and power charges up. Clear speed is stellar.
-Freeze and Shock: The extreme damage while critcasting will leave your enemies frozen and shocked, if not stunned or dead.
Easy to level: Leveling as a FP crit Witch is very easy.
No tree swap at high levels: You change your gear rather than the tree in your 60s to swap over. No regrets or respec points required.
-Map versatility: Blood Magic, 50% Regen, and No Regen are the only ones I'd suggest avoiding and I think that 50% Regen is doable sans AA. Elemental reflect is reasonable with Vaal Pact if you use the Life Leech gem and Berek's Grip; in testing, I've run dangerous Elereflect maps without much trouble, and I don't run elemental flasks.
High Level Arctic Armor: You can run lvl 23+ AA with this build. Ironically, the AA cost is a drop in the bucket compared to the regen/leech you need for the spell, so you can crank it up to extreme levels.
Atziri's Promise: This flask is tailor made for this build. Adding 15% extra elemental damage as chaos and 10% chaos leech makes you leech about 4,000 EXTRA life per second instantly in addition to whatever you were getting before.

Cons:
-Insane Mana costs: This build takes an expensive 6L spell and make it cost 80% more. It runs the highest level Arctic Armour on top of it.
-Positioning: FP makes you want to stand close. Lightning Warp helps a ton, but at the end of the day, you're doing your best damage at close range.
-Link hungry: This build really wants a 6L and due to the crazy mana costs, using Tabula Rasa is basically impossible. You can do this in a 5L, but you lose the Added Chaos gem, which adds huge amounts of damage (and leech through the flask). Running this version without the Life Leech gem I have discovered is inadvisable.
-Gear cost: This build handles a 5L better than the lvl 1 variant, but the rest of the gear can be very expensive. It's possible to run this build without Berek's Grip, but you have to work a lot harder for it; these are not readily available in the temp leagues and are expensive even in Standard. The build wants mana regen and crit on jewelry, resists crammed onto a very few items, and a high ES armor 5L. None of this is cheap.
-Wary of Elemental Spikes: Repeated hits from elemental sources (that get around Immortal Call) are the most dangerous thing. Especially when opening a box or fighting dischargers or caster Exiles, you have to be careful not to get overtaxed by elemental damage. Both the lvl 1 and lvl 20 variants have considerably more life than my original build did, so I am far less concerned about this issue than I used to be.
-Weak to Corrupting Blood: You can easily pick up 20 stacks of off-screen Corrupting Blood from GMP Freezing Pulse. MoM and AA do not do a thing to fight degen. Your reaction time to it if you stop leeching needs to be very quick. Note: The 1.3 flask changes help a ton here. A Surgeon's Divine Flask of Staunching does a lot of work now that it grants immunity during the effect. Having a non-instant flask largely solves this problem if your reaction time is okay.

The key to the build. Getting good chaos rolls is pretty important, as this constitutes the bulk of your base damage. Make sure to bless for the full 20% spell damage. The lack of a shield hurts your defense and puts some pressure on the rest of your gear to get resists elsewhere, as well as making you miss a good life mod.

Maligaro's is very strong for this build and should probably just be the choice. However, if you've ever been given an opportunity to use Voidbringer productively, the lvl 1 variant for this build is it. I think the drawback is just not worth it, but my original version of this character ran it just fine.

Originally, I used a life/resist/speed rare in this slot, but I think that Goldwyrm is just better for this build. 60% regen is just unreal. Movement with this build is very good even with only 10% here due to the random move speed in the tree, the removal of armor penalties with Art of the Gladiator, and a very fast Lightning Warp.

The armor is something that I have as a holdover from another era. I've not finished crafting it and that cold resist will someday be something better. Ideally, I'd be using hybrid armor/evasion chest and helm with some better numbers and top tier life, but this has been fine for now. These are the floater pieces that you devote to getting life, resists, ES/mana, and armor (if you can). I would suggest you house as much of your resists in these slots as you can so you can spend your jewelry suffixes on dps. My pieces have some pretty good numbers on them, but this works without a 700+ ES Vaal Regalia. I also think that a Geofri's Crest would not be out of line; my helm has pretty low ES for endgame, but the +1 level to gems for the auras might be worth the hit. Alpha's Howl is another option that gives you a stack of armor and aura levels for Grace and Clarity and some of your reserved mana back instead of giving you more flat mana. This will put a larger resist burden on other pieces of gear, though, which is why I have not chosen to use it.

Good crit jewelry is really helpful. I discovered I had the legacy amulet after spending a week trying to buy one. Derp. Putting it on jumped my dps by about 3K per GMP projectile as compared to a solid spell damage/crit chance amulet. It is totally worth it to have a legacy item like this if you are playing in Standard even with poor mods otherwise. Get what you can afford, but get one. If you are not playing in Standard, crit damage is still the most important roll followed by spell damage. I would also recommend as much mana regen as possible; this may be difficult to fit or expensive, but it is worth it when you can get it. I'd be much happier with a second high mana regen piece.

Berek's Grip is most useful to the lvl 20 build. It massively increases your mana capacity through leeching from shocked enemies. I do not regen enough to keep up with the insane costs of a dual Apep's 6L without it with the current tree. It can be done, but it is much cleaner to use this item to add a sizable leech. My intent is to try to eventually cut the life leech gem in the 6L using this to bridge part of the gap, but I'm not there yet.

The flasks I use are to combat my nemesis, Corrupting Blood. I cannot stress enough how easy it is to demolish yourself with bleed stacks. The Surgeon's Quicksilver Flask of Staunching is your friend; 6 seconds of immunity is just great. Atziri's Promise is ridiculous for the lvl 20 variant. With Vaal Pact giving uncapped leech and the large amount of both converted elemental damage and chaos damage you start with, you are basically invincible while attacking. The damage bump is solid too. You might even consider having more than one, but I've found it unnecessary. It's okay for the lvl 1 variant, but not essential; you only benefit from the leech and the resist. I am pretty bad with flask management, so I don't run elemental flasks, but Surgeon's elemental flasks of Stanching or Warding would also be pretty useful for those more adept.

6L
Freezing Pulse (lvl 1 OR 20)-Added Chaos-GMP-Life Leech-Crit Damage-Spell Echo
Using a lvl 1 Freezing Pulse makes the base mana cost 4. Even with 6+ casts per second, you are never going to have mana problems. The lvl 20 varaint is extremely expensive, especially with the Apep's penalties. Either way, the links are the same.
A 20 quality FP is very important. I only get 20% projectile speed in the tree, so quality is key for the 60% you get there. Added Chaos quality is also better than it is for other builds. A corrupted lvl 21 Added Chaos is an additional 23.5 average base chaos damage over a lvl 20. This is huge for the lvl 1 variant when you are only looking at about 380some with good Apep's and a lvl 20 gem. I have not been able to acquire one yet.
I would very much like to get PCoC into the link instead of life leech for the lvl 1 variant. In a 5L, I'd say that Life Leech is probably the most dispensable, but if your crit chance is not solid yet in mid levels, perhaps Crit Damage would be better to go without. CantripN's idea to bridge the gap with Atziri's Promise and Warlord's Mark might work better than removing a dps gem, as the damage drops a ton. I've had good success with using Warlord's Mark as my only leech on other builds, but those were melee builds that used Leap Slam and Herald of Thunder to apply the curse automatically. Being a bit at range goofs up Herald and I think that manual cursing would be the better choice if your survivability depends on it. However, at that point, maybe it is just best to stick with leech in the link to save curse time and get your charges from an automated Assassin's Mark. I think party makeup and average number of players in your party should factor into your decision, as solo play or an all-crit party will make getting charges from the curse easier. In a larger party with the lvl 20 variant, you can safely replace Added Chaos with PCoC to ensure you maintain charges. you lose a huge chunk of non-reflectable damage, but your charges are even more important.
While leveling, a leveled FP is better to use until your crit comes online and you can equip Apep's.
4L
Vaal Storm Call-Increased Duration-Spell Echo-[Added Chaos/Empower]
Initially, I ran a single-target Ice Spear here with PCoC-Added Chaos-Spell Echo. However, Vaal Storm Call is a more effective weapon to use on both single targets and groups. You can get a +2 Vaal Skills mod on a corrupted helm, boots, or gloves (especially good in a Geofri's Crest or Vertex); coloring Maligaro's or Goldwyrm once corrupted would be too much of a pain, I think, but Voidbringer or pretty much any helm you want for this build will work well.
4L
Herald of Thunder-Reduced Mana-Curse on Hit-Assassin's Mark
You spend most of your time shooting enemies at close range. The curse gets applied to most of your enemies. I have had no trouble shocking enemies with Herald of Thunder's added damage on either build variant. I could see going to a manual curse without this setup to get more unreserved mana for MoM, but once you go auto-curse, you just don't want to go back.
4L/3L
Reduced Mana-Clarity-[Grace/Discipline]-[Herald of Ice in non-MoM build only]
The auras for this build are straightforward. Clarity is vital to the AA/MoM plan. Grace and IR give a solid amount of armor. The lvl 20 variant might be better off ditching Grace/IR entirely for Discipline, but I have not tried it yet. Herald of Ice is not necessary for the build, but adds some solid damage and reduces stragglers. If you use Geofri's Crest or Vertex, putting the auras in it is pretty solid.
4L/3L
Lightning Warp-Reduced Duration-Arctic Armour
Technically, 2 and 1 is better, as the Reduced Duration lowers the ground ice time on AA. You don't need Faster Cast for Lightning Warp, as the cast speed for the build is really high. If you have foregone Herald of Thunder and have great mana regen, adding Empower in a 4L (especially in a Geofri's Crest) for 21+ AA may be warranted here. In that case, I'd swap things around to make this Arctic Armour-Assassin's Mark-Empower-Enhance and put Lightning warp on the remaining 3L. If you use Geofri's Crest or Vertex, putting this in it is even better than the auras.
3L
CwDT (lvl 1)-Enduring Cry (lvl 5)-Immortal Call (lvl 3)
Standard array of CwDT abilities. This is pretty important for this build.