Assassin's Whisper animation glitch

[BasiliskXVIII]

Not sure if this is actually a bug or just a really strange decision for the animation, but when you use the interruptible version of Assassin's Whisper, shortly after going into the "charge up" phase, a sonic wave effect flies sort of diagonally up and away from you. It doesn't do anything to the enemy, it's just kind of present. Then, about a half second later the attack proper fires and you get the power animation.. I don't know if this is a a power effect that's being called at the wrong time, or aimed at the wrong place, but it looks unintentional. (starts at about 1 sec into the attached clip)