You guys might want to look at this technique again as well. I'm practically 100% I just used this technique two different times in a single fight and got the same special zalian message both times. So it isn't just the first time with the zalian unearthly item equipped? Btw, the second time I used it most definitely wasn't a melee tech as the flying eye failed to evade it. Observe:
You flip a blade out of your strange bracer, suddenly stabbing the eye for 7 damage.
The eye beats its wings, flying above your reach.
The only thing that stops be from being absolutely positive about this is because I wasn't specifically looking out for this in this fight.
Edit: I figured it out. I neglected to mention that this happened in the fight against 3 evil eyes. The two instances of zalian blade being used was against two different evil eyes. The "first time you reveal the blade" applies to each different opponent.