[2.5] The Bastard Child - Life-based quick and versatile Quad Curser support. [Can do all map mods]

You are a support build, but also the party scout and leader; moving in the frontlines ahead of the group, making sure that everything is cursed by the time your teammates get there. What you bring to the party is incredible extra protection in the form of Enfeeble, Temporal Chains, and Warlord's Mark, and tons of extra elemental damage thanks to a combination of Elemental Weakness and Elemental Equilibrium. This results in a great clearing speed, seeing how your team won't have to play it safe, kite, or run away from the battle, and they will be destroying everything really fast thanks to the extra damage.
If you play it correctly, noone in the party -including you- will ever face the risk of dying to enemy attacks, and no enemy will stand a chance against you.

Your survival depends on quick reflexes and well-timed manual evasion that abuses your inredible speed and the slowed down movement of the enemies.

This isn't an idle support build where you do nothing but follow the group, or wait until the boss just to use a culling skill. Look elsewhere if you like the TV meta, as this build will demand skill and awareness from your part, and its low defenses will punish your mistakes.
On the other hand, if you enjoy a high action build and are up for the task, you'll find that this build is not only fun, but perfectly viable for all maps, mods, and tiers. Perhaps the exception would be Atziri, but it's nothing a flask of Warding cannot fix.

The general strategy is to run, cast your long-ranged Lightning Ball and curse everything on its path, then move to evade any monsters on incoming projectiles, and repeat.

Level 93

The tree is pretty simple; we're just going for curse bonuses, life, and a couple of jewels. There's no complicated witchery in play here. Level up as you prefer, I'd suggest going to the left side first for all the life nodes, since you don't need 4+ curses to complete the story mode.

We're getting Mind Over Matter to make use of all the extra mana we get from all the Intelligence nodes. Elemental Equilibrium was a though choice, but I decided to go with it, because after polling some people, I realized that Lightning damage is by far the least used type, and also, even with the EE extra resistance, the enemies end up with lower Lightning Resistance after getting cursed with Elemental Weakness, so in short; even in the worst case scenario, we're still buffing lightning damage builds a bit.

As for the ascendancy, we're going for Malediction and Void Beacon. The extra 2 points are unnecessary.

I always plan builds for 93 because I rarely bother grinding, maintaining a map pool, or playing it safe past that point, but if you enjoy leveling past that, you have different options for the remaining points; you could go for Conduit and mix it with a Culling Strike weapon, or just go for extra life nodes, or maybe get the flask bonuses or an extra jewel. Up to you.

Help Oak on Normal.
Kill everyone on Cruel and Merciless.

Arctic Armour for some extra protection and chilling. Haste because speed is life. You'll see.
I also carry a Purity of Elements for Elemental Weakness maps, but if you can overcap yourself, that's not required.

The core of the build. We'll be running a mostly defensive setup that turns enemies into useless crawlers that do nothing but feed life and mana to your party. In order to achieve this, we'll be running Enfeeble, Temporal Chains, Warlord's Mark, and Elemental Weakness. We'll also leave a free curse spot for that one guy who always thinks that their curse is better than those of a dedicated curser, and because running a 5th curse ourselves would make us less efficient at our job due to having to either hinder our cursing skill, or forcing us to use a different skill to cast it.

++ means that corrupting them above their maximum level or quality would benefit the build.
X means the value doesn't matter and can be anything.

Enlighten 3++/X
Arctic Armour 20++/20
Haste 20++/X
Vaal Haste 20++/X
Ball Lightning 1/0
Curse on Hit 20/20++
Enfeeble 20/20++
Greater Multiple Projectiles 1/20++
Faster Projectiles 20++/20++
Warlord's Mark 20/20++
Lightning Golem 20++/20
Purity of Elements 20++/X (Only for Elemental Weakness maps if you can't cap your weakened resistances with gear).

The rest are defensive and utility skills. Use whatever suits your playstyle the most.

The core of the build; you can't call yourself a curser if a mere Hexproof mod stops you, plus it gives us an extra curse. Corrupt it if you can afford it; extra resistances, or +1 would be beautiful.

Two free curses on hit. Can't ask for more. Corruption is obviously mandatory.

To prevent aurabots from screweing up our Elemental Equilibrium. Culling Strike is good to make the most out of Profane Bloom.
If you decide against Elemental Equilibrium, these would be good alternatives:
Corrupt with Culling strike for double Profane Bloom efficiency.
Just for the extra cast speed. Again, Culling strike is a nice addition.

Extra speed, chaos resistance, and the most important; extra Dexterity required for the gems and gear. Aim for a 30% extra Enfeeble effect chance enchant. If you can get your Dexterity and chaos resistance from other sources, you could go with a different helm. A Rat's Nest for more evasion and the extra speed, or even an Ylfeban's, just for the keks. Whatever your choice, go for an enfeeble enchant.

This is how we cap our chaos res. You could corrupt it if you manage to get enough with its explicit and the rest of your gear and nodes.

This one is just perfect for this build; extra speed which gives us more survivability and efficiency, projectile speed that allows the Lightning Ball to cover a larger area, and of course, an extra curse. Mandatory corruption for the extra curse.

Tons of speed. Extra speed enchant is sexy. If you can't find them because the league is young or whatever reason, then go with whatever rare or unique with 30%+ you like the best.

As for the remaining ring, the belt, and shield, just look for resistances and health. This is what I'm using. Nothing fancy:

Most of our flasks are for panic situations, and we should try to avoid using them as much as possible, because using them means we're doing something wrong, as the main defense of this build is to make the enemies dumb and slow, and then mix that with our +100% base extra speed to manually avoid all of their attacks.

The Quicksilver works for panic mode, and in case your party is extremely fast. Then we have a flask of staunching for bleeding, and the last 3 are the "OMG, OMG!!" panic button: Forbidden Taste and the Writhing Jar will instantly refill all of your health, while the Jar will also give you mana to recover whatever was lost due to Mind Over Matter. Then the Lion's will push and scare the enemies away, while granting knockback to your Ball Lightning.

As for jewels, Careful Planning is obviously there to satisfy our hight Dexterity needs, and to give a use to all of those Intelligence nodes that nobody needs. Conqueror's Potency gives a buff to our flasks, auras, and curses. Try to corrupt one with Silence immunity.