There are plenty of character builds in Path of Exile that have the potential to wreak havoc and devastation upon enemies throughout the game. This is mostly true for character builds that turned out to be popular later once more players try them out and see their effectiveness for themselves. Since Path of Exile is a game that encourages the kind of creative flexibility that gives birth to more character builds that are equally or even more effective than established ones, then it's no surprise that this build has come up to a good bit of attention lately.
The Dual Curse Pledge of Hands Arc build is quite a mouthful for a name, but it is merely a central concept that is augmented by a few others like pillars around a central column to create a strong build that is both cool and powerful at the same time. This particular build is all about critical damage of Arc, the active skill that shocks and chains multiple times to other enemies near the target, bringing them down with increased critical strike multiplier.
Even while it had still been a work in progress, it already was dishing out 26k in DPS, which is definitely substantial. What helps it get that powerful are mostly the other skills that support it and the Path of Exile items that make it all possible. What's notable about this build is that it actually makes use of two copies of Arc, each with a different set of support gems. This is where the little details start to really count, especially since it's such an intricate build.
The first copy is the primary damage dealer, while the second is for pre-cursing monsters before killing them off. Since Arc has such a good chain effect, it helps disperse curses quite easily, which is why this build makes use of two of them. It may seem clunky at first, but it actually works rather beautifully. Not only is it offensively effective, but the prodigious use of Life Leech and the Vaal Pact keystone makes for a powerful combination of critical damage, damage reflection, and survivability.
The curses are the Warlords mark and Assassins mark, which gives you life leech, mana leech, endurance charges, power charges, critical chance, and more critical damage. Aside from the curses, the other two main components of this build are Eldritch Battery and Pledge of Hands, the latter of which is where the name of the build comes from. Eldritch Battery's purpose is obvious enough, while Pledge of Hands is a unique Judgement Staff that gives the gems inserted in it a level 30 Spell Echo, which makes this build work.
Most of this build's survivability comes from a massive mana pool and Arctic Armour, and you can run more auras here if you wish and willing to sacrifice some unreserved mana if you need it. Beyond its main mechanism, there is a bit of flexibility that can lead to variations of this build to fit your particular playing style.
For more information on this build, this is actually been made a Build of the Week by Grinding Gear Games, and you can also look for the creator of this build FoxTactics on his own guide of this very build.