A/X
Critical Strikes 11+1
Dagger Mastery 12+1
Deadly Arts rest
Shadow Arts 6+1
Not sure where to put the mask yet, either Critical Strikes or Dagger Mastery.
Mark of Instability
Unsuspecting Strike
Black Lotus Strike
Twisting Fangs
Moebius Strike (E)
Critical Defenses
Return
Shadow Refuge
Zealous daggers would be nice for this build I think.
Next one~
A/R
Marksmanship 12
Wilderness Survival 8
Critical Strikes 10+1+1
Punishing Shot (E) or Broad Head Arrow (E)
Concussion Shot
Distracting Shot
Savage Shot
Read the Wind
Troll Unguent
Sharpen Daggers
<empty> maybe Needling Shot?
Not sure what to put into the last spot since I don't have a lot of experience with rangers, but I do love to interrupt and it's a good way to get myself through the missions if parties want anything but melee assassins.

I think Punishing shot would work better since it doesn't require so much energy but I dunno for sure. I would like some help in filling the last spot.
Was thinking a zealous bow for this, not too sure of the type. Might want shrouded armour for this too
Comments and Suggestions are welcome.