[2.4] The Charge Harvester Blade Vortex Assassin with budget version [MoM][Poison]

Replace Faster Casting with Added Chaos.
Add in Spell Totem - Wither to your setup somewhere. It'll help on single targets.
Consider swapping a scion duration cluster for the curse effectiveness cluster. 20 stacks can be sustained with spell echo and 1 duration cluster.

Our links are:
1. 6 link
Blade Vortex - Controlled Destruction - Faster Casting - Spell Echo - [Poison focused gem] - [Utility gem]
Where [Poison focused gem] is Void Manipulation while using a Cospri's Will and Poison otherwise and [Utility gem] is usually Increased AoE, but is switched to Physical to Lightning for Physical Reflect maps and Concentrated Effect for hefty bosses. We always use a 6 link in the main blade vortex setup. I'd use a Tabula for the 6 link before using a 5 link chest of a different kind.

2. 4 link
Blade Vortex - Curse on Hit - Enfeeble - Vulnerability
You can turn this into a five link by adding increased area of effect.
This setup should be cast so a stack from it is always up so you curse nearby enemies with these defensive and offensive curses, which causes you to poison them when using Cospri's Will.

3. 4 link
Faster Attacks - Fortify - Cyclone - Leap Slam
This setup is used to proc fortify, and cyclone is used on heavy targets to cause them to bleed. We want them bleeding so we gain 20% of physical damage as chaos damage when damaging them by way of the Assassin node, Toxic Delivery.

4. 4 Link (or 2 2-links)
Vaal Clarity - Increased Duration - Faster Casting - Flame Dash
Vaal Clarity is used to rev up stacks of blade vortex before bosses without losing the EHP we gain from Mana.

5. 4 Link
Vaal Haste - Cast when Damage Taken - Immortal Call - Increased Duration
Put this in The Harvest or Facebreakers as it'll be possible to easily color them for this setup.

Weapon:

If you can't get this weapon, don't do this build. Follow a Pathfinder Blade Vortex guide but use BV - ICS - FC - Spell Echo - Poison - Inc AoE/P2L/Conc Effect and a Doedre's for Vulnerability over an Essence worm for Hatred.
This weapon gives over 265 increased global crit chance at high player levels, and generic life leech on critical strikes, as well as a flask charge every time a critical blade vortex stack circles (assuming it hits once or more). With this weapon, our flasks are always up.

Chest Piece:

Cospri's Will is best-in-slot for our build as it gives an extra curse (freeing up a ring slot) and curse penetration and free poisoning of cursed enemies. Note that some enemies are flat out curse immune such as The Goddess in the Plaza map, so switch Void Manipulation for Poison in these cases.
Other good options are Carcass Jack and The Beast's Fur Shawl for increased AoE and area damage as well as good EHP. A Tabula is also workable, but for non-Cospri's chestpieces, you need to use poison instead of Void Manipulation.

Gloves:

We use Facebreakers for the 90% critical strike multiplier. I don't think anything can compare save for perhaps Atziri's Acuity for the instant leech on crit, which would free us from Vaal Pact.
For a Glove enchantment, Commandment of Spite is nice as it's a free CwDT - Arctic Breath. Commandment of Blades may help your clear speed a bit, but this enchantment slot isn't very important either way.

Belt:

For the belt slot, you want a rare belt with lots of life, a resist, and a high roll for reduced flask charges used. I prefer increased flask effect duration over another resist or strength.
I've actually been looking to upgrade to a The Retch for the massive amounts of flask effect duration, but that has been impossible to do this temp league as Talisman Legacy uniques aren't readily available.

Amulet:

You want good life, mana, crit multi, a resist, and whatever attributes you need for your gems on this piece. I needed 40-50 dexterity and 15 or so strength so I picked up this amulet.

Rings:


Rings are where we get to have some fun.
Before I go any further, you want to be res capped with only 1 ring on.
I always keep the first linked ring equipped, while swapping between the other 3.
You want 2 rings with very good resists, life, and mana. One of these you'll wear to cap your resists. The other you'll swap in to cap your resists in ele weakness maps (assuming your other gear is such that you need the resistances). Then you want one ring with the maximum amount of life and mana you can buy. This ring is your one-shot protection ring. It adds the most EHP possible so you have the best chance of surviving massive hits like those Uber Izaro, Uber Atziri, and some high tier map bosses deal. Finally you want a Ming's Heart, which you can safely use on most maps for the extra damage. On your Ming's heart, you can look for the (3-6)% damage taken gained as mana corruption, which synergizes well with Mind over Mana.

Helmet:

Max out the life, mana, and resistance rolls on this piece. Defenses don't matter, these will come from flasks and enfeeble.
Regarding Helmet enchantments, Vulnerability Curse Effect, Blade Vortex Duration, and Blade Vortex Radius are what I would recommend. I finally got Blade Vortex Duration at lvl 93, and it hasn't felt much different at all. It takes the duration from 9.6 sec to 11 sec.

Boots:

On boots, you want maximum life and mana, as well as elemental resists. Move speed is not a requirement but I'd recommend it as it's nice to have another 30%. That said I leveled past 90 before buying move speed boots and clearing felt fine.
For a boot enchant, I'd recommend either life/mana leech if you've killed recently or life/mana regen when hit. These help sustain our massive mana costs if our Vinktar's is down.

Offhand slots:

I run a Brightbeak in my mainhand with a 3-green Prismatic Eclipse in my offhand for super fast leapslam travel. This is nice for when my quicksilver flask is all used up or I don't want to spend its charges.

Reorder these as you please, I'll refer to them how I slot them for ease of reference.
Getting these specific rolls can be a pain. Early league I'd settle for Seething instead of Bubbling, and increased duration/reduced charges used over the increased flask effect rolls.
Slot 1: The Recovery Slot

I run the divine through Uber Lab as I get 5 uses as opposed to 3 and I run through traps with not a care in the world. Otherwise, the Hallowed Hybrid is probably a better choice as it works well in no regen maps and tops up both life and mana which you want if you're taking large hits (as you do when fighting Uber Atziri, Colosseum Daresso, etc.).
Side note: With enough increased flask effect and increased life gained from flasks, Bubbling flasks restore more instantly than Seething (true instant) flasks do. So we use these.

Slot 2:

This gives a flat 31% physical damage reduction and dispels the shock that Vinktar's gives us.

Slot 3:

Taste of Hate takes us to 82% Cold Res and converts 26% of physical damage to cold damage, thus negating 26*.82 = 21.32% of the physical damage dealt to us.

Slot 4:

This flask is core to our build. I recommend buying it before a Taste of Hate. It gives us massive life and mana leech, sustaining both these pools. It also shocks nearby enemies, so we kill things nearly 50% faster. With this build, it refills in like 2 seconds.
You need to get the phys conversion version (the spell damage might work, but I don't think it would be as good. Haven't tried it personally).

Slot 5: The Leeway Slot

In this slot, I usually run my Alchemist's Quicksilver of Adrenaline for over 100% movespeed from one flask. For fighting Atziri herself I use the Ruby flask for maximum Fire res (84%) and to dispel the reflected curses. If I want to nuke a boss super quickly or just do more damage in a rough map I'll use Atziri's Promise. Finally, if I am worried about getting stunlocked by something like Core Malachai's tentacles or I'm worried about getting frozen I'll use Kiara's Determination.

Bandits are Oak, Kill, Alira although Normal and Cruel are debatable (take your preference).

Level 93, 114 points
Level 84, 105 points
Level 54, 75 points
Level 35, 56 points

Jewels:
We use Clear Mind for the massive spell damage boost, since we are Mind over Mana.
On other jewels, get life along with some double-dipping modifier (Increased Area Damage, Increased Damage, lesser so Increased Chaos Damage) and I prefer getting Increased Cast speed along side the other mods although this is mainly a QoL choice.

Ascendancy:
We obviously choose Assassin.
Pick up Unstable Infusion, then Deadly Infusion.
After that pick up Noxious Strike and then Toxic Delivery for the juicy 100% more Poison damage on crits.

Increased AoE Tooltip Warrior
Increased AoE Mapping
Conc Effect Tooltip Warrior
Conc Effect Mapping
Defenses with Ming's
Defenses with Max EHP

Basically, swap Cospri's for a Tabula and Void Manipulation for Poison.
Use Doedre's in your spare ring slot and run a Quicksilver/Diamond flask with the elemental resists suffix for ele weakness maps.
Also swap Taste of Hate for a Granite flask of Iron Skin (Alchemist's if possible).

For a super budget version, go Pathfinder instead of Assassin and use Void Batterys or a Divinarius or two. Swap Controlled Destruction out for Increased Critical Strikes and your crit rate will be decent. I'd recommend rolling with a diamond flask as Pathfinder with that setup.

2.3 List (harder Core Malachais, lower tier Vaal Temple):
Deathless Uber Atziri run
Facetanking Plaza Bosses regardless of mods
Core with all bosses down with -16% max res (took all 6 ports and died to a trap as Malachai popped)
Core with all bosses down with elemental reflect (took 2 ports)
Cores with less scary mods (deathless a few times)
Deathless Twinned Vaal Temple (with help of an aurabot so more max res and significant armour)
Deathless Twinned Colosseum with Vuln and +97% Lightning damage with 3 man HP
Deathless Twinned Abyss runs
Atziri runs with 5-6 man HP
Uber Lab runs with 6 man HP
Ghosted Uber Argus (I believe it was Seditionist's Grip).
Abaxoth facetanking in a t12 with temp chains.
Twinned Core (Ele Weakness and +80% lightning resist, died twice to avoidable Malachai slams)
Marathoned 13 Uber Lab Runs (Conduit + Essences) on 2 man HP going about 10 min/run. Died once to my router completely destroying my connection (I couldn't load web pages... so I sure as heck couldn't avoid traps).

Legacy Conversion Vinktars is amazing for this MoM build, and lets you spec out of Vaal Pact.
Legacy Taste of Hate will give more defenses.