"High delay for a dagger so you should offhand a dagger such as hornetneedle or sirocco kukri if subbing ninjar."
Offhanding Hornetneedle is never really a good idea for THF. The delay is pretty but the base damage is so lacking that your DoT will drop far more than if you had just offhanded a slower but higher damage dagger. Sirocco works because it has 162.5% the base damage of hornetneedle as well as an added wind effect on every strike.
These daggers also appear to do light dmg to mobs. It has happened several times since I started using these, yet no where has reported it. I don't know if it has to meet certain conditions or whether it's just a hidden effect.
The Harpe for the THF on a budget. In a nutshell ^^b. High delay for a dagger so you should offhand a dagger such as hornetneedle or sirocco kukri if subbing ninjar.