From Guild Wars Wiki
Eye of the North
|Bonus||Armor +15 (while attacking)|
A Nightstalker's Insignia is an assassin specific upgrade component that provides an armor bonus of 15 extra armor rating while you are attacking. This bonus is not global and applies only to the armor piece equipped with the insignia.
|Armor +15 (while attacking)|
- This insignia only drops in Factions and Eye of the North.
- 1Priests of Balthazar will have this insignia available for unlocking on accounts without Factions even though such an account cannot create Assassin PvP characters.