"A special armor worn mostly by assassins. Its increased flexibility makes it easier for its wearer to strike vital points in their opponent's body."
Obtained From: The Keystone Monastery
Notes: Chest and Helm found in Spider room next to the poisoned Monk.
Set Bonus: Increases Critical Hit Damage by 50% (Confirmed 12/28/17)
I've seen that my riposte (parry-counter) damage dropped from 322 to 215 when I broke up this set. That would imply a 50% bonus to critical hit damage.
Please test and edit if someone else can confirm this as well.
Tested with multiple weapons on different mob types. Consistently 50% increase. Damage boost also applies to Backstabs
-An anon helper