Have you not been using a sin build before?
There is nothing a Sin can't handle in GWEN, I mean, you have faced basically everything there is right?
Burning, poison, crippling, death nova, daze, weakness, disease, high damaging melee, high damaging spells, burning, holy damage, etc. The only thing I can see that you may think about is your build for the Norn Tournament.
Otherwise, its the same tactics as normal, let warriors run in first, you come in and spike, shadow out if you get hit, etc.
I've only ventured into GWEN with two characters (Monk and Ritualist), so specific builds for specific areas, I can't help you (my Assassin is still in NF).