Vale Sin

I see the advertisements for vale sins a lot, but I really don't know what they are, what they're used for, and how they work. I was given a build by someone. A/N. Deadly Paradox, Shadow Form, Golden Lotus Strike, Lotus Strike, Death Blossom, Chilblains, Shadow Refuge, and Death's Charge
Dagger Mastery 8, Curses 8, Shadow Arts 10, Deadly Arts 10.

Vale sins are used for UWSC groups. The "vale" is the area they are to clear.
They work with a necro to clear.

http://pvx.wikia.com/wiki/Build:Team...ld_Speed_Clear

what he said, but your build isn't right, you need 12 in shadow arts to maintain sf and you don't need points in deadly arts

UWSC = Underworld Speed Clear.
Vale = one of the areas
Vale Sin = perma-sin that goes with a necro to enforce their will on that area