Twin Fangs
Hidden Blades
Flank Attack
Stealth
http://da-skills.net...0,010,1C100,110
This build allows you to 1 shot dangerous enemies (treasure room guardians, assassins like shadow and fear demon, despair demon etc) with Hidden Blades, as well as nearly taking down the room 5 boss.
You are constantly able to be in stealth, so you never have agro with the I Was Never Here passive. It is excellent, and a must have on Perilous, if they see you, you're toast.
I tend to find myself taking out the assassins in the group before the group is pulled with HB, re-stealth, then position behind the archers. Twin Fangs usually can 1 shot each of them (hopefully you're using some good daggers), or you can get it real close. Then re-stealth and kill more archers.
You're mobile with Flank Attack, and it works like an o-sh*t button if you do end up with agro, as you can disappear behind your enemy when stealth isn't available.
I use the Blade of Red Birth in my main hand, and Agony in my offhand.